Practice Test -- Momentum, Center of Mass (Mr. Rogers AP Physics C )

Unit Plan Practice Test Study Guide
    Online Quiz - Momentum                                                              8BBD-445C
1 ) Find the center of mass of a triangular shaped object of length L with the following height = 1.5 L. Assume uniform thickness and density. Show all work. Xcm = 2/3 L, Ycm = .5 L
2 ) A 2 kg mass is located 1.0 m directly above a 1.0 kg mass. A third 3 kg mass is located 2 m directly to the right of the 1.0 kg mass. find the location of the center of mass. Xcm =  1.0 m, Ycm = 1/3 m
3 ) A 0.5 kg bullet hits a 25 kg ballistic pendulum and causes it to rise by 0.5 m. Find the initial velocity of the bullet. Vb = 161 m/s
4 ) At an intersection, a car of mass = 2m and velocity v plows into a car of mass = 3m going through the intersection from a perpendicular direction at the same speed. The cars stick together. Find the final velocity's magnitude. Vf = 0.72 m/s
5 ) A billiard ball collides with another billiard ball. The first ball goes off at an angle of 30 degrees with respect to its original velocity. What is the second ball's angle with respect to the first ball's original velocity. 60 degrees, It's the complement of 30 degrees
6 ) Two objects collide elastically in outer space. During the collision the force is as follows: F = 25 t^3. The collision lasts 0.5 sec. What is the magnitude of the change in momentum for each object?

Imp = F(t) ∙ dt

      = 25 t^3∙ dt

      = 25 (1/4) t^4

      = 25 (.25) (.5)^4

      = 0.3906

7 ) Coal drops at a  rate of 10 kg / sec. on a conveyor belt  moving at 2 m/s. How much force is required to keep the belt moving at constant velocity?  

F = dp/dt

    = V (dm/dt)

    = (2 m/s) ( 10 kg/s)

    = 20 N

8 ) Bob crashes into a tree when he is traveling at 30 m/s. His truck has a mass of 1500 kg. Find the impulse during the collision. 45,000 Ns
9 ) Is impulse a vector? Yes
10 ) Does impulse follow Newton's 3rd law? Yes
11 ) Can Newton's 2nd law be stated in terms of momentum?  ΣF = dP/dt

SAM Team--Southside High School's STEM and Computer Science extra-curricular club (Mr. Rogers Sponsor)

Mr. Rogers' Twitter Site

Mr. Rogers Teacher's Blog

Mr. Rogers T-shirts

Mr. Rogers Information for Teachers

Mr. Rogers Science Fair Information

Check out other web sites created by Mr. R:

Check out Articles by Mr. Rogers:

Insultingly Stupid Movie Physics is one of the most humorous, entertaining, and readable physics books available, yet is filled with all kinds of useful content and clear explanations for high school, 1st semester college physics students, and film buffs.

It explains all 3 of Newton's laws, the 1st and 2nd laws of thermodynamics, momentum, energy, gravity, circular motion and a host of other topics all through the lens of Hollywood movies using Star Trek and numerous other films.

If you want to learn how to think physics and have a lot of fun in the process, this is the book for you!


First the web site,

now the book!

Mr. Rogers Home | Common Sylabus | AP Comp Sci I | AP Comp Sci II | AP Physics Mech | AP Physics E&M | AP Statistics | Honors Physics|IB Design Tech | Southside

[ Intuitor Home | Physics | Movie Physics | Chess | Forchess | Hex | Intuitor Store |

Copyright 1996-2011 T. K. Rogers, all rights reserved. Forchess is a registered trademark of T. K. Rogers.
No part of this website may be reproduced in any form, electronic or otherwise, without express written approval.