Mechanics PHYS200

This is the course page for my PHYS200 (Mechanics Fall 2014) students.

Get help for free in the help room – schedule here: 2015s_tutor_schedule.

Course Documents:

Syllabus (version 11/24/2014).
Problem Solving Template for maximizing partial credit.
Equations sheet for exams and studying under testing conditions.

When we use physlets, there could be issues with compatibility on the classroom PCs.  If that happens, you may access the activities via this website: compadre.org.

Clickers:

The bookstore has a physical version and depending on availability, Sherry in the department office (CS101) brokers the sale of used physical clickers.  A cheaper option, available as an app for Android or iOS devices, is available too.

Homework:

Unless otherwise noted (Obj = Objective, Con = Conceptual), these numbers indicate items from the “Problems” section at the end of each chapter.  A selection of problems will be collected for grade, and they are annotated after the lists (ie. Due 9/10…), but you should be able to solve all the problems I assign (and more) if you expect to do well on exams.

Mechanics HWOne:

Ch1:     Obj5, Obj8, 2, 5, 6, 10 (and dimensional analysis), 11, 14(a), 28, 29, 45
Ch2:     Obj1, Obj3, Obj18, Con1, Con3, 15, 19
Ch3:     Obj12, Obj13, Con1, Con2, 1, 4, 12, 28

Due 9/10 (chapter.problem #): 1.2, 1.6, 2.15, 2.19, 3.4, 3.28.

Mechanics HWTwo:

Ch5: Obj1, Obj3, Obj4, Obj6, Obj10, Con4, Con7, Con13, Con19, 2, 3, 6, 7, 15, 18, 19, 20, 21, 26, 30 (a, b only), 34, 35.

Start using the problem solving template linked above.

Due 9/22 (chapter.problem #): 5.6, 5.26, 5.30 (a,b), 5.34, 5.35.

Mechanics HWThree:

Ch5: 42, 46, 49, 51, 57, 60, 63, 66, 70, 72, 74

Must use the problem solving template linked above.

Due 9/29 (chapter.problem#): 5.46, 5.49, 5.51, 5.63, 5.66.

Mechanics EXAM 1:

Happened 10/1

Mechanics HWFour:

Ch2: Obj5, Obj14, Obj15, Con6, Con7, 21, 28, 29, 30, 44, 46, 51, 52.

Due 10/8 (chapter.problem#): 2.Obj5, 2.Obj14, 2.Con7, 2.21, 2.28, 2.30, 2.51.

As a curiosity, here’s my take on the classic mechanics exercise, “the monkey problem.”  Equating the position vectors for “any time” belonging to the apple and bullet (my version is friendlier to monkeys) gives an identity.  This proves that, assuming the shot is aimed at the apple and the apple falls when the shot is fired, it will always hit the apple.  It doesn’t matter if the shot comes from a slingshot or a sniper rifle.  The slingshot will just hit the apple closer to the ground.  Many versions of this exist and there are many great explanations on the web: do a search for “monkey hunter problem mechanics”.  Here is one nice example with obvious ties to your lab activity 3.6.2.

Mechanics HWFive:

Ch2: 41, 55
Ch4: 9, 12, 15, 20, 21, 23, 25

Due 10/15 (chapter.problem#): 2.55, 4.12, 4.15, 4.21, supplemental (below).

Supplemental problem.  Revisit item 5E of exam 1: now assume the incline sits on a tabletop that is 1.00m high and that the edge of the table is at the low end of the incline (so the block is in free fall when it reaches the end of the 2.00m incline).  a) What are the velocities in the horizontal and vertical (not parallel and perpendicular) directions at the end of the ramp?  b) How far in the horizontal direction does the block land from the end of the incline?  c) How long had it been in free fall when it lands?

Mechanics HWSix:

Ch4: 33, 35, 37, 38, 40, 42, 43

Due 10/22 (chapter.problem#): 4.35, 4.37, 4.38, 4.42.

Mechanics HWSeven:

Ch7: Obj1 (and explain why), Obj2, Obj6, Obj7, Obj14, Con8, Con10, 3, 5, 6, 9, 14, 17, 31, 37, 38, 42

Due 10/29 (chapter.problem#): 7.Obj2, 7.Obj14, 7.Con8, 7.14, 7.17, 7.31, 7.38.

Here’s a very brief clip of a lecture given by Walter Lewin at MIT with an exciting take on the pendulum.

Mechanics HWEight:

Ch.7: 52, 53, 55, 59, 63, 64
Ch.8:  3, 6, 9, 12, 13, 14, 15, 18, 32, 33, 36

Due 11/5 (chapter.problem#): 8.3, 8.6, 8.12, 8.14, 8.15, 8.36.

Mechanics EXAM 2:

Happened 11/10

Mechanics HWNine:

Ch.9: Obj7, Obj8, Obj9, Obj10, Obj12, Obj13

Due 11/12 (chapter.problem#): 9.Obj7, 9.Obj8, 9.Obj9, 9.Obj10.

Mechanics Activity 6.3

Use these measured quantities to determine the muzzle speed for the steel ball:
m(steel ball)=65.85g
m(pendulum)=243.9g
length(pivot to pendulum bob)=30.05cm
average steel ball theta=36.5degrees

Once you have the muzzle speed for the steel ball, you can predict what the angle theta will be for the lighter plastic ball:
m(plastic ball)=9.85g

Is the muzzle speed the same for the plastic and steel balls?  The muzzle speed is imparted by the gun’s spring.
We’ll do the final part (verifying your prediction) on Monday.

Mechanics HWTen:

Ch 9: 12, 14, 15, 17, 30, 32, 33, 35, 38, 39, 44, 50, 71, 77
Ch10: Con9, Con11, 2, 10, 13, 27, 28

Due 11/19 (chapter.problem#): 9.17, 9.12, 9.32, 9.35, 10.Con9, 10.Con11, 10.13, 10.27.

Mechanics HWEleven:

Ch10: 29, 36, 44, 45, 48, 53, 63, 64, 87
Ch11: Con9, 5, 11, 15, 22, 24, 26
Statics Lab Stations Questions: All

Due 11/26 (chapter.problem#): turn in statics problems from lab and 10.29, 10.53 , 11.Con9, 11.15, 11.22.

Mechanics EXAM 3:

Happened 12/3

Mechanics HWTwelve:

Ch13: 6, 9, 12
Ch15: 6, 7, 8, 20, 22, 24

Due 12/10 (chapter.problem#): 13.9, 15.7, 15.8, 15.20, spring write-up.

Pendulum demo:

calculate T and omega for the two trials with 200g mass and varied length for the pendulum and bring to class.  Do the same for the below tests where the length was held constant with varied mass:

(I did two runs each, just use the average time to get the period)
20 oscillations in {31.77, 31.82}sec with 62cm length and 200g mass
20 oscillations in {32.17, 32.03)sec with 62cm length and 500g mass
20 oscillations in {32.17, 32.05}sec with 62cm length and 500g mass

“Galloping Gertie” :
Here’s a catastrophic example of a driven oscillator.  The Tacoma Narrows Bridge collapsed in 1940 after winds caused oscillations at a natural frequency.

Mechanics Final:

Happened 12/15