Elastic Collisions
Inelastic Collisions
Impulse
Momentum
General
100
In an elastic collision, this is what happens.
The objects "Bounce" off each other
100
What happens in a inelastic collision?
Two objects "stick" to each other and combine their masses
100
What is an impulse?
Force applied over time to change momentum
100
What is momentum?
The vector quality of motion an object has
100
Can momentum be negative. Explain
Yes because momentum is a vector quantity
200

What is the momentum equation for an collision between two objects where initially one object explodes into two?

m1 v1i = m1 v1f + m2 v2f

200

What is the equation for two moving objects that collide and stick together?

m1 v1i + m2 v2i = (m1 + m2) vf

200
What is the equation for an impulse?
I = F x t
200
What is the equation for momentum?
P = m x v
200
In an elastic or inelastic collision, if the momentum of the second object is "0", what can you say about the velocity?
It is stopped
300
What can you tell me about the following equation? m1 v1i +m2 v2i = m1 v1f +m2 v2f?
Two objects are moving before they collide and once they collide, momentum is conserved
300
How can you show that two objects are traveling in opposite directions in an inelastic collision equation?
Show one with a negative velocity
300
What is the equation to solve for force in a change of momentum problem.
F = Pf - Pi / time


or 

F = (change in) P / time

300
What are the units for momentum?
kg x m /sec


or 


N x sec

300
What has to happen to the impulse force if the impulse time is decreased. What can we say about the relationship of impact force and impact time?
The force increases
400
A 2 kg ball traveling at 2 m/s strikes a 4 kg ball at rest. The struck ball travels the same direction of the ball that hit it at .5 m/s. What is the speed of the 2kg ball after the collision.
1 m/s
400
A 40 kg object is traveling at 4 m/s toward a 5 kg object that is traveling the same direction at .5 m/s. If they collide and stick together, what will their final velocity be?
3.6 m/s
400

What is the impulse applied to an object that stops an 8 kg object traveling 4 m/s?

32 N x sec
400
Find the momentum of a 4 kg object traveling at 40 m/s.
160 N x sec
400
How can the momentum of a car equal the momentum of a bus?
Fast moving car, slow moving bus
500
2 objects of equal mass collide and both move in the opposite directions. What can you conclude?
The two collide and transfer their momentum to each other
500
A 114 kg running back running down field at 5 m/s has a defender 91 kg collide with him and hold on for dear life.  The defender was motionless before the collision, what is the velocity of both players after the collision?
2.8 m/s
500
What is the force applied to an object that stops an 8 kg object traveling 4 m/s in 2 seconds?
16 N
500
Find the momentum of a 5 kg object that covers 40 m in 2 seconds.
100 N x sec
500
If the momentum of an object is great, how does that relate to the impulse variables used to stop the same object.
Impulse force has to be greater and/or time has to be greater in order to change its momentum to zero.
M
e
n
u