Section

  • WELCOME TO PHYSICS AT ISM.  I'M GLAD YOU ARE TAKING THIS COURSE.
    You are reading our official class website.  This is THE PLACE for my communication to you in this course.  
    I expect you to look at it at least once a week to see assignments, updates, reminders, and notices.  Every Sunday night I add the following week.
    This site is not locked, so your parents and guardians are encouraged to use it and see what you are doing.  Please give them the link.
    You should always check here before you start your HW assignment, and you can subscribe so you'll get an email when I update it.
    I'll also post advice, clues, cartoons, current events, and fashion advice.
    Physics can explain so much, such as could you really put a passenger train through a loop-the-loop as shown here .  
    The answer is here: http://what-if.xkcd.com/43/

    Check out these videos:  Do you want to help fly another stratospheric balloon this year?
       
      
  • I hope you saw the big eclipse one week ago!

    This is the first week in the course webpage for Physics at ISM!

    I use a blog format, so each week I'll add a new entry with assignments and information.  YOU MUST LOOK HERE AT LEAST EACH WEEK.

    I UPDATE THIS SITE ON SUNDAY NIGHT, USUALLY.

    HW due  (If any assignment isn't clear then you have the responsibility to clarify and/or correct.  Telling me you didn't understand the assignment when it is due WILL NOT BE AN ACCEPTED EXCUSE.)

    • due Tue: write name on edge of your text in dark marker--show me (yes, you must always bring your text to class)
    • due Wed: read through section 1-5.   Turn in a plot of altitude vs. time for this launch  [if you can't read this youtube video, then go to https://serc.carleton.edu/dmvideos/players/mars_space_labo.html?hide_banner=true  ]
    • due Friday: Explain, as best you can, the physical phenomena happening during the ping pong cannon launch and the short flight and collision of the ball.
    • HW due next Tuesday: 1, read p xviii, read through 1:1-7: web: do physlet below, print one page showing physlet.
      • problems to hand in: chapter 1: Q7; P 8, 9, 12, 14, 15, 19  (P = problem, Q = question)
      • also due Tuesday: show plot due Wednesday using Excel for all calculations and show a fit of the data points, with the equation of the fit.

    We will use many physlets, which are "physics applets". They are cool.  Here's the first one assigned for next monday.

    special assignment: one-on-one with Dr. F-- come see me by 5 sept -- I need 5 min to ask a few questions and get to know you

    Week 1 Points:  (this is a rough list of what I expect you to learn in a week.)

    • know how to access all class information and how the class will work
    • be able to distinguish doing science from learning about science
    • Differentiate dogma from observation
    • Know the standard units in the SI system and how big they are
    • Know and show how to use the fishbone method of conversions

    How scientists think.......

  • NOTE: if you miss completing some HW, you need to do it for the next class.  

    special assignment: one-on-one with Dr. F-- come see me by 8 sept -- I need 5 min to ask a few questions and get to know you

    HW due Tuesday:

    • HW due next Tuesday: 1, read p xviii, read through 1:1-7: web: do physlet below, print one page showing physlet.
      • problems to hand in: chapter 1: Q7; P 8, 9, 12, 14, 15, 19  (P = problem, Q = question)
      • also due Tuesday: show plot due Wednesday using Excel for all calculations and show a fit of the data points, with the equation of the fit.

    We will use many physlets, which are "physics applets". They are cool.

    HW due Wednesday: Complete both sides of worksheet Sig Figs Practice.  Also, use the inside front cover of your text to calculate: density of moon, density of earth, density of sun; report as kg/m3.  Finally, do these 6 calculations and manage sig figs.  1.   5443002      2.  π + 3    3.   π / 3     4.   π / 3.00000

    5.    1.8x105    x   4554000      6.  0.004533 + 0.2799 + 20 + 4500

    HW friday: 1: p-1, 2, 13, 17, 21, 45;   Also, find the file "website assignment" in FILES and do that for today.

    HW new for next Monday:  chapter 1: Q-3, 4; P-3, 4, 5, 23, 43; measure your bedroom, report volume in SI units, sig figs 

    Points for this week:

    • show ability to solve problems with units and Conversions
    • Know which numbers of inside front cover to memorize
    • Demonstrate significant figures and their use
    • Understand science, what is physics, and how we were all experimentalists
    • Know the use of “measurement”, “precision”, “accuracy” in science

    Dimensions

    If you see these stick people then I'm using comics from xkcd.com.  He studied physics and worked at NASA before making the world of science and engineering and math funny and poignant for us.

  • HW for Monday:  chapter 1: Q-3, 4; P-3, 4, 5, 23, 43; measure your bedroom, report volume in SI units, sig figs 

    Quiz Tuesday: scientific notation, sig figs, and a simple calculation. 
            and in class we will measure the thickness of paper

    HW due Wed:  chapter 1: COQ (chapter opening questions) 1-2 (see page 1).  MCQ (MisConceptual Questions) 1,3,5,6

    HW due Friday: 2: COQ; Q 1-9; P 1,2,3,4,5,9,17   

    NOTE: we are now done with chapter 1 in class, although you need to keep up practice with sig figs.  The slides from class are posted above under Powerpoint .....  You can use them to study and review, or to relive those great times we all had in room 309.

    HW due next Monday: chapter 2: Q 10, 11, 15; P 23, 25, 27, 61, 62.       Also for this physlet, http://phet.colorado.edu/en/simulation/moving-man I want you to try many cases of acceleration.  Set up a condition where the man moves with negative velocity but positive acceleration, and print that condition of the physlet.

    1. Points: Velocity: average and instantaneous
    2. Show that x, v, t in kinematics work for any, including final xf, vf, and tf
    3. Acceleration, average and instantaneous
    4. Understand kinematic equations for Motion at constant acceleration
    5. Be able to plot x, v, and a vs. t for simple 1-D motion
    6. Demonstrate the solution technique for kinematic problems 

  • Warning: this is a critical period for this course. The new concepts such as graphing and defining a problem that we are starting will be used all year. Do NOT fall behind in chapter 2 or 3. If you are not following the material in class or the problems, please come see me!

    I have open hours posted, I'm here after school, and we have Physics Study Group on Tuesday 5th.   Stop by and see me.

    HW due Monday: chapter 2: Q 10, 11, 15; P 23, 25, 61, 62.       Also for this physlet, http://phet.colorado.edu/en/simulation/moving-man I want you to try many cases of acceleration.  Set up a condition where the man moves with negative velocity but positive acceleration, and print that condition of the physlet.

    Tuesday:  2: Q 12, 13;  MCQ 4, 6, 9;

    HW due Wednesday:  2: P: 6, 11, 26, 27, 31, 39

    HW due Friday: retreat

    HW due next Monday:  2: P- 7, 41, 45, 55,  69, 71,be able to draw the first 2 motion graphs (use Moving Man on PHET for help)

    next week: bowling ball lab--kinematics

     Points:

    • Demonstrate memorization of kinematic equations
    • Demonstrate use of kinematics in freefall problems
    • Show memorization of sketch/list/choose method
    • Show memorization of symbolic first, then numbers
    • Demonstrate ability to draw 6 basic graphs of x,v,a vs. t as handout
    • Add “avoided variable” list to kinematics table in the text

    remember how we talked about how narrow the human experience is....check this out for a sense of perspective.

  • NOTE THAT CLASS SLIDES ARE NOW POSTED ABOVE IN A FOLDER.

    HW due Monday:  2: P- 7, 45, 55,  69, 71,  

    HW due Tuesday: Do this practice problem.  It would be worth 20 points on the exam. 
    Find the final velocity of a rock that falls 25m for each case below;  for each part, solve first in symbolic form, then plug in the numbers.

    • a. if the initial velocity is zero.
    • b. if the initial velocity is +5.0 m/s. It is thrown up into the air.
    • c. if the initial velocity is -5.0 m/s. It is thrown down.
    • d. comment on the answer for b and c. they should be the same. why.?

    Be able to draw all 6 motion graphs.  (use Moving Man on PHET for help)  

    HW due Wednesday: complete the practice exam which I will hand out on Tuesday, and also is in files at top if you want to start early.

    HW due Friday: Exam 1 in class.  Bring your calculator.

    HW due next Monday: we start chapter 3.  read 3:1-5, do 3: COQ; Q:1-4 P:1,3  

    You should be reading chapter 3 and have the first 4 sections reviewed before class on monday.   Turn in chapter 3: Q 5-8, P 2,4 and use this physlet to show addition of vectors;  http://phet.colorado.edu/sims/vector-addition/vector-addition_en.html  

    Also, start to play with the projectile motion PHET, although you don't need to print anything.  http://phet.colorado.edu/en/simulation/projectile-motion

    points:

    • Show list of into to be written on the exam: kinematic eqns, steps to solve, conversion factors
    • Demonstrate memorization of kinematic equations
    • Demonstrate use of kinematics in freefall problems
    • Show memorization of sketch/list/choose method
    • Show memorization of symbolic first, then numbers
    • Demonstrate ability to draw 6 basic graphs of x,v,a vs. t as handout
    • Learn how vectors work

    VECTORS IN DAILY LIFE......... 

  • HW due Monday:  HW due next Monday: we start chapter 3.  read 3:1-5, do 3: COQ; Q:1-4 P:1,3     

    due Tuesday:   Calculate velocity for the bowling ball from Monday and then calculate acceleration on the ramp.  We will compare your numbers to Loggerpro GoMotion data.

    You should be reading chapter 3 and have the first 4 sections reviewed before class on Tuesday.   

    due Wednesday :  HW is chapter 3: Q 5-8, P 2,4    We will demonstrate friction of falling objects.

    HW due Friday:   3: MCQ 1, 2, 3, 4, 5, 6. and play with this physlet to show addition of vectors;  http://phet.colorado.edu/sims/vector-addition/vector-addition_en.html 

    HW due next Monday:    3: Q-10, 17, 18; P-5, 7, 9,11  show, using this physlet, what angle gives the maximum range for a given firing cannon.   http://phet.colorado.edu/en/simulation/projectile-motion .

               In class we will perform the lab "projectile motion of a ball".    Your assignment is to read and know the lab before class.

    points:

    1. you will start solving projectile motion problems this week.
    2. know what a vector is
    3. demonstrate how to add vectors graphically
    4. demonstrate how to resolve a vector into its components
    5. show how to add vectors by components and find the resultant vector
    6. demonstrate how to do projectile motion on the level
  • to get perspective, and to remember that the physics we are learning applies to all this..... ....

    HW due Monday:   In class we will perform the lab "projectile motion of a ball".    Your assignment is to read and know the lab before class. 
    3: Q-10, 17, 18; P-5, 7, 9,11;  show, using this physlet, what angle gives the maximum range for a given velocity of cannon.   http://phet.colorado.edu/en/simulation/projectile-motion 

    HW due Tuesday:    none

    HW due Wednesday:  3: Q-11, 20, P-17, 19, 21.   

     HW due Friday: P- 20, 23, 39, 55, 59.   (2 hints for #23:  (sinX)(cosX) = 1/2 sin(2X), and sin(2X) = sin(180-2X)) 

    HW due next Monday: 3: MCQ 7-12; p- 18, 23 (do this problem experimentally at home; bring a picture to prove you did), write the list of classic problems for chapter 3 in your notebook.

     Points: this is the week you master projectile motion

    • demonstrate how to do projectile motion on the level
    • demonstrate how to do projectile motion off the cliff
    • demonstrate how to do projectile motion up off the cliff
    • demonstrate how to do projectile motion down off the cliff

  • to continue our journey, this app includes the jouney to the smallest places http://htwins.net/scale2/  

    Lab update: the video files are located in the J drive and in FILES.  I moved the due date to 27 October.  A scaffold of your report can be found in FILES.  You are free to use this.

    HW due Monday: 3: MCQ 7-12; p- 18, 23 (do this problem experimentally at home; bring a picture to prove you did), write the list of classic problems for chapter 3 in your notebook  I'll review HW from friday P- 20, 23, 39, 55, 59.  (hints for #23:  (sinX)(cosX) = 1/2 sin(2X), and sin(2X) = sin(180-2X)) 

    Due Tuesday: before class, have in your possession all the distance data for each run (steel or glass) of lab 2 in a table with your name on it.  Bring that and show me.   there will be a quiz on one of the first two classic problems in chapter 3 (cannon on the level or car off a cliff)

    Also Due Tuesday:   in this video, a car is pushed into the river from 18 stories.  I timed the fall at 3.2s.   I estimate that the car fell 120 feet horizontally away from the building (the range).  Using your physics, calculate the height of the fall and the horizontal velocity as it left the building.  Report in SI units and in mph (miles per hour).  

    Wednesday: look at the PHET cannon launch again, and find two different angles of the launch that give the same Range.  Write down both angles and bring that to class.  https://phet.colorado.edu/sims/projectile-motion/projectile-motion_en.html .  

    Due Friday: CONFERENCES

    For next Monday, show me that you have done the loggerpro analysis for the launch velocity of your steel ball off the ramp.  The videos are posted in the J:drive under our class (and also in FILES above, but you'll have to download them from the website before you can import them to Loggerpro).  If you plan to do the analysis at home, you will need to transport the data to your home via email or a USB-drive or from the website.  You should plan on 30 minutes for this work the first time. Look at Using Loggerpro On Videos under Physics Tools for step by step instructions.  Also use Help in Loggerpro.  You are in the digital generation, so i'm confident that you can figure it out.

    due Next Tuesday: Read sections 4-1 through 4-4; 4:COQ 1; Q-1,2,3,4,5 and: Q- 5, 8; P-1   and    is a nice ESPN analysis of high jump.  The jumping jumper jumps 93 inches, but his center of mass we'll assume goes up to 87 inches.  Assume he lands on the same level (even though he really lands on the tall pad).  How long is he in the air?  I estimate that his forward travel, the Range, is 72 inches.   So what is his vx at takeoff?  what is the angle θ of his launch?

    points this week.
    Be able to write the steps for solving projectile problems.
    Know the requirements for completing a lab report
    Know Newton's first and second laws of motion
    Know that force is a push or a pull

  • Welcome back.  If any of you wish to know what I reported to your parents/guardians during the conferences, please see me and I'll happily tell you.  If they didn't come to conferences, but you want to know, I'll happily tell you.

    Due Monday, show me that you have done the Loggerpro analysis for the launch velocity of your steel ball off the ramp.  The videos are posted in the J:drive under our class (and also in FILES above, but you'll have to download them from the website before you can import them to Loggerpro).  If you plan to do the analysis at home, you will need to transport the data to your home via email or a USB-drive or from the website.  You should plan on 30 minutes for this work the first time. Look at Using Loggerpro On Videos under Physics Tools for step by step instructions.  Also use Help in Loggerpro.  

    Due Tuesday: Read sections 4-1 through 4-4; 4:COQ 1; Q-1,2,3,4,5, 8; P-1  

    and   is a nice ESPN analysis of high jump.  The jumping jumper jumps 93 inches, but his center of mass we'll assume goes up to 87 inches.  Assume he lands on the same level (even though he really lands on the tall pad).  How long is he in the air?  I estimate that his forward travel, the Range, is 72 inches.   So what is his vx at takeoff?  what is the angle θ of his launch?

    Due Wednesday:   4: Q-9, 10, 11,12, 13;  P-3, 5, 7   Using this video of a car skidding on ice, find the acceleration during the stop.  Note that the car starts slowing at 0m on the scale. http://serc.carleton.edu/dmvideos/players/prius_skids.html?hide_banner=true 

    Due Friday:  Lab report on projectile motion.  Turn it in at the beginning of class.

    HW due next Monday: 4: Q-14, 15,16, 17, 18; P-11, 12,15, 17, 70; play Robot Moving Company (use tab 4), try for max score. Bring in print of your top score. http://phet.colorado.edu/en/simulation/forces-and-motion

    goals for this week:

    • learn and demonstrate the steps to do ΣF=ma problems
  • NOTE: I also posted a practice exam in FILES.

    The study guide for the exam will be handed out Tuesday.

    HW due Monday: 4: Q-14, 15,16, 17, 18; P-11, 12,15, 17, 70; play Robot Moving Company (use tab 4), try for max score. Bring in print of your top score. http://phet.colorado.edu/en/simulation/forces-and-motion

    HW due Tue: 4: MCQ 1, 3, 7, 8; P- 20,26,37,39,41

    HW due Wednesday: Do these three problems: 1) In an experiment like your recent lab, you found the steel ball landed 85cm from the launch, and you measure vo using video analysis to be 6.44 m/s.  Given this data, what is the height of the table launch point?  Derive the equations you need starting from the kinematic equations.  2)  I throw a ball up in the air and it lands at my feet, 1.5m lower than where I released it.  The time of total flight is 2.00 s.  a) what initial vertical velocity did I throw the ball?  b) How high did I throw the ball? c) if the ball landed 3.5m from me, what was the initial horizontal velocity of the throw?  d)  If I was on the moon, how high could I throw that same ball?

    HW due Friday: solve these versions of some classic problems.  Show all parts of the solution neatly on your paper.

    classics 2 & 3:  You, on a sled, slide from rest down an ice hill of 30o.  There is no friction.  What is your acceleration, and how fast are you going after 15 m?  Then you hit a muddy portion of the same slope, and you stop in 10.m.   What is the coefficient of friction on this muddy portion?

    classic 4: You have mass of 65kg.  You take your scale to the elevator and stand on it.  What is your weight as the elevator goes up at a=0.22m/s2.  What is the weight as the elevator goes down at a=0.33m/s2

    classic 5: You, at 65kg, jump from an airplane and freefall with air drag of 150. N.  What is your acceleration?  Then you open the parachute, and slow down to a constant falling speed of 8.0 m/s.  What is the drag force of the parachute through the air?

    Classic kinematic: A basketball bounces up from the floor at 55o and hits the floor 9.0 m further.  With what velocity did it leave the floor?  How high will it bounce?

    classic rope:  You need to cross an aligator infested river.  You find a rope tied 2.0m above the water to trees that are 33m across the river, and the rope has a tension of 1200N.  Your mass is 55kg.  Can you make it without touching the water?

    Next Monday:  You can rewrite up to 3 points of corrections for the projectile lab.   That is due Tuesday.   Exam 2 in class     (the study guide was handed out and is posted in FILES)

    Points/objectives this week

    • demonstrate in HW and check problems how to do F=ma problems
    • develop a list of classic problems for chapter 4
    • show that you can capture data from an experiment.

  • HW Due Monday:   Exam 2 in class     (the study guide was handed out and is posted in FILES)    

    Due Tuesday: You can rewrite up to 3 points of corrections for the projectile lab.    we will cover the effects of g forces on the human body.  (NASA report)

    WE DAY is wednesday.   Let me know on Tuesday if you will attend WeDay

    HW due Wednesday:study section 5-1&2. 5: COQ 1,2; Q-1, 2,3,5, 6,  

    HW due Friday:  5: P-1, 3, 5

    HW due next Monday:  5: Q-4,6,8,9  5: P-2, 5

    HW due next Tuesday: 5: P-7,8,11,15

    goals for week:

    • solidify chapter 4 classic problems and how to solve
    • apply F=ma to the ping pong cannon
    • learn the language of circular motion
    • be able to do kinematics for circular motion
  • Image result for physics gifs

    Even kittens can learn physics.

    HW due Monday:  5: Q-4,6,8,9  5: P-2, 5.   

    HW due Tuesday: 5: P-7,8,11,15.

    And Wednesday: FINALS START.    GOOD LUCK.   COME SEE ME WITH ANY QUESTIONS OR TO PRACTICE PROBLEM SOLVING.

    • demonstrate that you know: 
    • •Cannon on the level
    • •Car horizontal off a cliff
    • •Ball up off a cliff, find final velocity only
    • •Ball down off a cliff, find final velocity
    • •Throw a ball up to a cliff ledge
  • Welcome to Term 2!  We have 3 busy weeks before break, so please stay focused and you'll be rewarded by Santa.

    HW due Monday: none, but be sure to review chapter 5 sections 1-3, and read 5-5 and 5-6.  (we will skip section 5-4.)  

    Tuesday: Calculate for the centrifuge running at 3300 rpm: period, T; frequency, f; speed of the tube; centripital acceleration in the tube; g force developed; the force ("weight") of 3.0 grams of water in the tube.  The following problems were due before break, so make sure you have them done:  5: COQ 1,2; Q-1, 2,3,5, 6, P-1, 3, 5.   Shoot the PP canon in class for the next lab.

    HW due Wednesday:  this was also due before finals:  5: Q-4,6,8,9  5: P-2, 5,7,8,11,15 so please review them, and new problems 5: Q-11 (draw a sketch to show answer), 12, 13, 14; P-69 

    HW due Friday: 5: Q-15,17,21; P-12,28,29 

    HW due next Monday:   5: MCQ 1, 2, 3, 5, 7, 8; P: 33,43,45   and show me your Loggerpro analysis of the ping pong cannon. The video is posted  in FILES and in the J drive. It was shot at 1000 frames per second.   Show both the x vs. t and the v vs. t plots.

    goals for this week:

    • Demonstrate solutions of the flat turn with friction and banked turn no friction.
    • Know the universal gravitation law, and know that it forms the most important centripetal acceleration in the universe
    • Be able to solve satellite problems

  • HW due Monday:    5: MCQ 1, 2, 3, 5, 7, 8; P: 33,43,45   and show me your Loggerpro analysis of the ping pong cannon. The video is posted in FILES and in the J drive. It was shot at 1000 frames per second.   Show both the x vs. t and the v vs. t plots.        

    HW due Tuesday: open Energy Skate Park physlet basics listed below and operate it with and without friction; write by hand a copy of the energy bar graph for the friction case and describe in a few words what the bar graph shows..   

    HW due Wednesday:  chapter 6: Q-1,2,3,4,5,6; P-1, 3, 5, 9 ,17,18 

         Given what you know of the time for the earth to circle the sun, and the distance to the sun, calculate the mass of the sun;  

    HW due Friday:    6: MCQ 1, 5, 6, 7, 8; Q-9, 10,15,17; P-20, 21,26, 27, 31   
              Look at this ISS video before class:      

    HW due next Monday:   6: Q-12, P-29, 23; 
           Write the 8 classics for chapter 5 in your notebook.  Find them on the powerpoint slides posted above.

    in class we will perform the energy minilab

    HW due next Wednesday: 1 page data analyzed for in-class minilab on energy.  Show that the measured potential energy equals the measured kinetic energy.  Show that the measured work to lift the object equals the PE and KE.  And what fraction of the energy is lost to friction.

    Demos: spring jumper or dart gun

    Friday Mini lab: in class falling objects measured. Do energy balance.  

    Physlets: Energy skate park: http://phet.colorado.edu/en/simulation/energy-skate-park-basics

    Points for this week:   

    • learn and use kinetic energy, potential energy, and work
    • show you can do work problems with and without friction
    • be able to define energy and relate this to work.
    • calculate energy expended for simple operations
  • HW due Monday:   6: Q-12, P-29, 23;   .

    (we will do the energy minilab in class.  as usual, if you miss the minilab, come see me to get the information.)

    HW due Tuesday: Ping Pong minilab is due.    Look carefully at the assignment sheet.   

    HW due Wednesday: 1. Calculate how much work you do to climb the stairs from my lab to the 400 floor (up one level).  2.  Using energy methods, find the average force needed to accelerate a 66g rocket from rest straight up so that at 550m elevation it is travelling at 330m/s.  Start with Wnc = ΔPE + ΔKE.  

    HW due Friday: Do we have class.  Read the info below on the physics of Santa Claus.  What is the KE of the fully loaded sleigh travelling at full speed??

    Points for this week:

    1. show that you can determine the velocity of a falling object with and without friction
    2. know how to calculate the work done by friction on a sliding object
    3. demonstrate that you can analyze all the energy terms of the jumping bug
    4. calculate the power of a person climbing the stairs

    THE PHYSICS OF SANTA CLAUS.   http://www.snopes.com/holidays/christmas/santa/physics.asp   

    I. There are approximately two billion children (persons under 18) in the world. However, since Santa is a Christian myth, this reduces the workload for Christmas night to 15% of the total, or 378 million (according to the Population Reference Bureau). At an average of 3.5 children per house hold, that comes to 108 million homes, presuming that there is at least one good child in each.

    II. Santa has about 31 hours of Christmas to work with, thanks to the different time zones and the rotation of the earth, assuming he travels east to west (which seems logical). This works out to 967.7 visits per second.

    This is to say that for each household with a good child, Santa has around 1/1000th of a second to park the sleigh, hop out, jump down the chimney, fill the stockings, distribute the remaining presents under the tree, eat whatever snacks have been left for him, get back up the chimney, jump into the sleigh and get on to the next house. Assuming that each of these 108 million stops is evenly distributed around the earth (which, of course, we know to be false, but will accept for the purposes of our calculations), we are now talking about 0.78 miles per household; a total trip of 75.5 million miles, not counting bathroom stops or breaks. This means Santa's sleigh is moving at 650 miles per second -- 3,000 times the speed of sound. For purposes of comparison, the fastest man-made vehicle, the Ulysses space probe, moves at a poky 27.4 miles per second, and a conventional Reindeer can run (at best) 15 miles per hour.

    III. The payload of the sleigh adds another interesting element. Assuming that each child gets nothing more than a medium sized Lego set (two pounds), the sleigh is carrying over 500 thousand tons, not counting Santa himself. On land, a conventional Reindeer can pull no more than 300 pounds. Even granting that the "flying" Reindeer could pull ten times the normal amount, the job can't be done with eight or even nine of them -- Santa would need 360,000 of them. This increases the payload, not counting the weight of the sleigh, another 54,000 tons, or roughly seven times the weight of the Queen Elizabeth (the ship, not the monarch).

    IV. 600,000 tons traveling at 650 miles per second crates enormous air resistance -- this would heat up the Reindeer in the same fashion as a spacecraft re-entering the earth's atmosphere. The lead pair of Reindeer would absorb 14.3 quintillion joules of energy per second each. In short, they would burst into flames almost instantaneously, exposing the Reindeer behind them and creating deafening sonic booms in their wake. The entire Reindeer team would be vaporized within 4.26 thousandths of a second, or right about the time Santa reached the fifth house on his trip. Not that it matters, however, since Santa, as a result of accelerating from a dead stop to 650 m.p.s. in .001 seconds, would be subjected to forces of 17,500 g's. A 250 pound Santa (which seems ludicrously slim) would be pinned to the back of the sleigh by 4,315,015 pounds of force, instantly crushing his bones and organs and reducing him to a quivering blob of pink goo.

    V.  Finally, remember that Santa lands on the roof of each house, and there are at least three reasons each house would be destroyed completely.  First, the weight of the reindeer and sleigh, as shown, will crush the house.   Second, the reindeer and sleigh while flying have a momentum of 6x1013 kg*m/s, and must stop in less than 1/10,000 second, giving a Third Law force on the roof of 6x1017 N, or over 6 billion tons.  Third, the heat of all those exploding reindeer would incinerate the rubble.

    Sunita Lyn "SuniWilliams née Pandya [1] (born September 19, 1965) is a former American astronaut and a United States Navy officer. She holds the records for longest single space flight by a woman (195 days),[2]total spacewalks by a woman (seven), and most spacewalk time for a woman (50 hours, 40 minutes).[3][4]

    Williams was assigned to the International Space Station as a member of Expedition 14 and Expedition 15. In 2012, she served as a flight engineer on Expedition 32 and then commander of Expedition 33.

    This is the YouTube tour we watched.  

    File:Sunita Williams.jpg

  • Welcome back, and happy new year!  Amazing things will happen in physics this year, and you will be part of that journey.

    HW due Tuesday:  6: Q-12,18,19; P-4,16,33,47, 29, 23

    HW due Wednesday:  turn in table for energy minilab.  Include your name, date, and 2-3 sentences of comments about the energy account for these objects falling.  Your spreadsheet will do the following: show the potential energy, the kinetic energy, the Work of friction, and calculate the fraction of the energy that is lost to friction.  The Excel spreadsheet in FILES and in J: drive must be used .  The Energy Minilab data are posted in FILES and in the J: drive.  You must open those files with Loggerpro.

    HW also due Friday: We will do a unit on the physics of car crashes.  To start, go to http://www.iihs.org/iihs/ratings and enter the BRAND, MODEL, and YEAR of the vehicle you ride in the most.  Print the first page of the report with some safety info (you can print the Full Report but it will be a lot of pages).   And then watch the crash videos in the video tab.  Describe how effective your vehicle is at protecting the driver during a crash.  (for extra credit, do Loggerpro analysis of the crash to find acceleration of the test dummy.  The measure tapes are 24 inches long.)

    HW due next Monday: 6: P-58, 59, 73

    Learning points for this week:

    1. be able to identify the classics for chapter 6.
    2. demonstrate that you can calculate power of a run up the stairs
    3. Know how to do all of the classics for chapter 6.
  • It is almost time for collisions.   Here are some.  https://www.youtube.com/watch?v=llv8BFB_k-A&list=PLbIZ6k-SE9Sj1Mj8X1rfFcGr8IZfEjPrB

    HW due Monday: 6: P-58, 59, 73

    HW due Tuesday: 6: P-75, 77, 79;  study chapter 7 sections1-2,
    using this physlet http://phet.colorado.edu/en/simulation/the-ramp, tab "more features", and find the minimum work to push the filing cabinet on flat ramp from 0 to 30m (full length) with friction coefficient of 0.3. Can you get less than 4500J for W applied? print and turn in page of minimum answer

    HW due Wednesday: .6: MCQ 1-8; and  chapter 7:COQ 1,2

    HW due Friday: ; 7: Q-1-3; P-1,3, 7  quiz on one of the energy classics (Let's see how you are doing learning this energy stuff)  The study guide will be handed out.

    HW due next Monday: no school!  

    HW due next Tuesday:   7:Q-4-6;  P-2, 4, 11, 15 

    HW due next Wednesday: 7:Q-7,8,11,12,13; P-17, 25, 68, 71  (quiz on simple momentum similar to P-3)

    Demos: air hockey pucks; get the bachristochrone and demonstate

    Points:

    1. show your ability to solve all classics in chapter 6
    2. Understand language of linear momentum
    3. Relate force to momentum
    4. Understand why momentum is conserved and how to use this
  • HW due Monday: no school!  

    HW due Tuesday:   7:Q-4-6;  P-2, 4, 11, 15 

    HW due Wednesday: 7:Q-7,8,11,12,13; P-17, 25, 68, 71  (quiz on simple momentum similar to P-3)

    HW due Friday: exam 1; the study guide is posted in FILES.

    HW due next Monday: 7: Q-14 P-17, 25, 33, 68, 71, 76

    Demos: air hockey pucks; get the bachristochrone and demonstate, ask question.

    Goals for this week:

    1. Have in notes the list of classic momentum problems
    2. Show ability to derive the ballistic pendulum solution
    3. Know that impulse is the one-body change of momentum
    4. Solve elastic collisions, and know the KE lost
    5. Solve completely inelastic collisions, and know the KE lost
  • HW due Monday: 7: Q-14 P-17, 25, 33, 68, 71, 76  

    HW due Wednesday: 7: MCQ 1, 2, 5; P-19, 35, 67

    HW due Friday: in FILES, Chapter 7 classic problems in momentum 1-3; and from text MCQ 7, 11

    HW due next Monday: Look at this physet, •http://phet.colorado.edu/en/simulation/collision-lab, and check all the options on the right.  then do an elastic collision and a completely inelastic collision.  Write the effects on energy, on momentum, and on the speed of the CM.  Do the same in the Advanced tab, and explain why the CM changes direction.   7:P-69, 73, classic problems sheet 4-6

    HEY consider this for summer fun.  http://www.mnasm.org/camp/ 

    Momentum Lab: conduct Monday Jan 29 in class

    Schedule: Mon: completely inelastic 2-d: point out classic problem sheet

    Points:

    • Have in notes the list of classic momentum problems
    • Solve 2-d collisions of completely inelastic type, any angle
    • Show ability to use Loggerpro video analysis for new lab

  • ....will the show choir tour affect our 14 Feb exam??.......

    HW due Monday: Look at this physet, •http://phet.colorado.edu/en/simulation/collision-lab, and check all the options on the right.  then do an elastic collision and a completely inelastic collision.  Write the effects on energy, on momentum, and on the speed of the CM.  Do the same in the Advanced tab, and explain why the CM changes direction.   7:P-69, 73, classic problems handout #4-5

    Due Tuesday: none

    HW due Wednesday:   7: Q-15,16, P-10, 29, 75. 
    Read carefully the assignment so you are well prepared for the momentum lab during class today

    HW due Friday: bring x vs. t and y vs. t plots for your momentum lab collisions; the data are posted on the J: drive in our class folder;
    NOTE: you are tracking two objects, so use the Set Active Point button  to start the points for the second object.  See Video Analysis in Loggerpro in Physics Tools for help on this.  

    HW due next Monday: 7: P-21, 37, 72   Classic Problems #6-7 in Momentum in FILES. 

    HW due next Tuesday: Complete all data in the lab table for your objects  use the best info or estimate of time of collision that you can obtain.

    Schedule: 
     finish chapter 7

    Next week: chapter 8, and the lab is due

    Points:

    Know how to solve all 8 classic momentum problems

    Design an experiment to test water balloon to the head

    Show ability to use Loggerpro video analysis for lab

    Show ability to solve momentum and kinetic energy problems 

  • http://www.mnasm.org/camp/ is a good summer camp to consider.  it is free.  4 days. 

    HW due Monday: 7: P-21, 37, 72   Classic Problems #6-7 in Momentum in FILES

    HW due Tuesday:   Complete all data in the lab table for your objects  use the best info or estimate of time of collision that you can obtain.  Do 3 problems from the Momentum Practice Test in FILES.

    HW due Wednesday: do all 5 "sample exam questions for term 2 exam 2" in FILES.   Do two problems from this website http://www.physicsclassroom.com/calcpad/momentum/problems

    HW due Friday:   NOTE CHANGE:  Turn in typed and complete analysis section of momentum lab.  See the example foundation report I handed out and that is posted in FILES.

    HW due next Monday. Lab report on momentum is due today.     THE EXAMPLE REPORT IS POSTED IN FILES UNDER THE EXPERIMENT.  I wrote this in 45 minutes from scratch, so I hope your writing takes less than 2 hours total.  I had to pick a particular case for my example, and I expect you to write your own words for the parts that are specific for your collision.  If you use my words, give me credit at the beginning ("Portions of text taken from Dr. Fisher Foundation Report").  Please make sure you have the lab report guidelines in front of you while you write.  

    Exam 2 is next Wednesday, Valentine's Day!.   The slides for chapter 7 are posted and the study guide is posted.

    Schedule: 
    Mon: problems, hand out practice problems, review lab analysis, discuss lab report

    Thur: momentum and a balloon (volunteer needed), classic problems, review, "turn around" review of chapter 7

    Points for this week:

    1. show that you can do all the classic problems of chapter 7
    2. demonstrate understanding of the calculations used in the lab spreadsheet.
    3. Understand and demonstrate that the primary goal in a lab report is to clearly and accurately describe what you did and what you found; this is much more important than doing all the steps of the lab or calculation correctly.
  • HW due Monday:  Lab report on momentum is due today.     THE EXAMPLE REPORT IS POSTED IN FILES UNDER THE EXPERIMENT.  I wrote this in 45 minutes from scratch, so I hope your writing takes less than 2 hours total.  I had to pick a particular case for my example, and I expect you to write your own words for the parts that are specific for your collision.  If you use my words, give me credit at the beginning ("Portions of text taken from Dr. Fisher Foundation Report").  Please make sure you have the lab report guidelines in front of you while you write.  

    HW due Tuesday:  do all 5 "sample exam questions for term 2 exam 2" in FILES   do any 8 additional problems from the "Momentum practice test" in FILES

    Wednesday: Exam 2 in class or ITL

    HW due Friday:   NO SCHOOL!

             study gravity:  

    HW due next Tuesday: bring your first exam from this term to class.  Do this problem:  A child and sled of mass M slide down a hill of vertical height H onto a frozen lake.  There is no friction on the hill.  On the lake, there is a friction coefficient of μ.  How far will the child slide before stopping?

    Points:

    review, review, review

    Some more practice problems

    1. A particle of mass M collides elastically (in one dimension) with a particle of mass 3M.  The initial velocity of mass M is v and mass 3M is initially at rest.  Determine the velocity of each particle after the collision.  Which particle experiences a greater change in velocity?

    2. How many 500g snowballs will I have to throw at 5m/s to accelerate myself from rest to 1m/s on frictionless ice?  My mass is 60kg.

  • This section

    The Final Exam is 160 pts, 12 problems total.  3 are definition/concept, 4 are problems (symbolic), and 5 are problems (numeric).  Counting all the sub-parts, there are 25 separate questions so you get about 5 minutes each.  I'm trying to encourage you to practice solving problems so you can do these smoothly.  

    HW due Monday:  presidents day.

    This is Revision week.   YOU need to decide where to best spend your time.   Many of you have probably forgotten how to do energy problems, so that is important for review.

    HW due Tuesday: (a few students gone on show choir trip)   bring your first exam from this term to class.  Do this problem:  A child and sled of mass M slide down a hill of vertical height H onto a frozen lake.  There is no friction on the hill.  On the lake, there is a friction coefficient of μ.  How far will the child slide before stopping?

    HW due Wednesday: Write the lists of classic problems for chapters 6-7.  Do these two problems both symolically and with numbers:  
    1.  A spring of constant k=2000N/m is pushed down on the table a distance of 5.0cm.  a)  How much force is needed to hold it there?  b)  When released, how high will it go?  c)  How fast will it be going just before it hits the ground? 
    2.  A 2000kg car is speeding at 44 m/s on a wet road, μ = 0.3.  The driver locks the breaks on.  a)  how far will the car skid before stopping?  b) how much heat will be dissipated by the skid?    c)  If he was instead going the speed limit of 55mph, how far would he skid?

    HW due Friday: solve 2 classics from each chapter 7 and 8 and solve them.  And do this problem.  1)  A cannon ball of mass 12kg ans speed 15 m/s hits and sticks to an ice house of mass 750kg on the lake.  a) how fast will they be going after the collision?  b) If μ = 0.1, how far will they slide before stopping?   c)  if instead the ball bounces off elastically from the ice house, how fast will the house be going after the collision?

    review the practice problem from Wednesday in class.
    1. A mass M on a ramp length L and angle Θ slides halfway without friction.  What is speed at 1/2 way point?
    Then is slides the rest of the way with Ff friction.  What is speed at the end of the ramp?
    (numbers L=100, Θ = 20o, M = 30kg, F = 3.0N)
    Answer: this is a two stage problem, so break it into a simple ramp and friction ramp.
    NOTE: I won't expect you to do FBD on this exam, so I changed that part.
    Note: it's possible that friction is so high that it will stop on the ramp, so your answer may show that.

    goals for this week: be able to write a map of the content for chapters 6-8

    Study hint: what is on the study guide or important in class that we haven't been tested on this term?

    Points for this week:

    • Be able to define radian, angular velocity, angular acceleration
    • Show proficiency in doing kinematics with rotational kinematic equations.
    • Define rolling motion and distinguish from simple rotation
    • Define torque, relate to force, and calculate torque
    • Solve simple second law rotation; τ = Iα