Download Unit Objectives: Understand the technique for finding center of mass

AP Physics 2013-2014
Unit 7- Momentum, Impulse, Collisions
Unit Objectives:
 Understand the technique for finding center of mass so you can:
 Identify by inspection the center of mass of a body that has a point of symmetry
 Locate the center of mass of a system consisting of two such bodies
 Use integration to find the center of mass of a thin rod of non-uniform density, of a plane lamina of
uniform density, or of a solid revolution of uniform density
 State, prove and apply the relation between center-of-mass velocity and linear momentum, and between
center-of-mass acceleration and net external force for a system of particles
 Define center of gravity and use this concept to express the gravitational potential energy of a rigid body in
terms of the position of its center of mass
 Understand impulse and linear momentum so you can:
 Relate mass, velocity and linear momentum for a moving body, and calculate the total linear
momentum of a system of bodies
 Relate impulse to the change in linear momentum and the average force acting on a body
 State and apply the relations between linear momentum and center-of-mass motion for a system of
particles
 Define impulse, and prove and apply the relation between impulse and momentum
 Understand linear momentum conservation so you can:
 Explain how linear momentum conservation follows as a consequence of Newton’s Third Law for an
isolated system
 Identify situations in which linear momentum, or a component of the linear momentum vector , is
conserved
 Apply linear momentum conservation to determine the final velocity when two bodies that are moving
along the same line, or at right angles, collide and stick together, and calculate how much kinetic
energy is lost in such a situation
 Analyze collisions of particles in one or two dimensions to determine unknown masses or velocities,
and calculate how much kinetic energy is lost in a collision
 Analyze situations in which two bodies are pushed apart by a spring or other agency, and calculate
how much energy is released in such a process
 Understand frames of reference so you can:
 Analyze the uniform motion of a particle relative to a moving medium such as a flowing stream
 Transform the description of a collision or decay process to or from a frame of reference in which the
center of mass of the system is at rest
 Analyze the motion of particles relative to a frame of reference that is accelerating horizontally or
vertically at a uniform rate
Unit Outline
Date
Topic/Activity
Assignments
M 12/2
Day 4
 Impulse & Momentum
 Conservation of Momentum

W 12/4
Day 1
 Elastic & Inelastic Collisions

Th 12/5
Day 2
F 12/6
Day 3
 AP Momentum Problems

~Science Drop~

HW #19 (due Mon., 12/9): pg. 268-70
E: #1-5,9,11,13,14,17,19,20,24,
26,28,29
HW #20 (due Fri., 12/13):pg. 270-75
E: #34,36,41,42,43,47,48,67,69,
73,82,83,86,91,95,106
M 12/9
Day 4
W 12/11
 Quiz: Momentum & Impulse
 Investigation: Momentum, Energy and Collisions
Project Wrap-In
Early Dismissal
Th 12/12
Day 1
F 12/13
Day 2
M 12/16
Day 4
T 12/17
Day 4
12/20/13 1/5/14
1/6 – 1/10
M 1/13
Day 4
W 1/15
Day 1


 2-D Collisions
 Center of Mass
 Solid Bodies







Motion of a system of particles
Exploding projectile
Rocket propulsion
2-D AP problem
Problem session
 Test: Momentum
NO School
Winter Break
WINTERM

HW #21(due Tues., 12/17): pg. 27172 E: #51,53,54,55,56,58,59
HW #22: Problem Handout
optional – extra credit
HW #23 (due Tues.,12/17): pg. 27276
E: #61,62,63,65,68,108,109


( We’ll discuss procedure in class)


 Test: Momentum (corrections)/review

 Angular position, velocity, acceleration (Unit 8)
 Angular & Translational Quantities (Unit 8)

Answers to even #’d problems (from book) are on Haiku…..
Complete Data Analysis
HW #24 (due Thurs., 1/23): pg.299301
E: #1,3,5,8,9,11,13,15,16,18,21,22,
23,26,29