Momentum Basics
Collisions (1)
Collisions (2)
Center of Mass
Impulse
100
What is the formula for momentum?
p=mv
100
What is the difference between an inelastic collision and an elastic collision?
The kinetic energy in an elastic collision is conserved, whereas it is not during inelastic collisions.
100
What is true of all closed system collisions?
The total momentum of the system is conserved.
100
What is the center of mass?
The weighted average of the locations of objects/balance point of the system/center of density or something similar.
100
Impulse is equal to what 2 things?
Force times time and change in momentum.
200
Momentum has units of what?
kg m/s
200
Car x is travelling in a straight line at a velocity of 2 m/s. It collides with the identical car Y after 5 seconds.
Create a graph showing (a) the velocity of car X over time and (b) the velocity of car Y over time.
You just gotta know this one Schaefer.
200
the 1 kg block comes to a stop. Determine the post collision speed of the 2 kg block.
1.5 m/s.
200
What is the center of mass velocity?
The speed at which the center of mass for a system of objects moves.
200
A 60 N force is applied to a 40 kg object for 3 seconds. Given that the the object started off moving at 20 m/s and the force is applied in the same direction as the object's motion, what is the object's final speed?
24.5 m/s
300
What does it mean when we say that momentum is a vector quantity?
It has direction as well as magnitude (size).
300
A train car of mass m traveling with a speed of v collides with a stationary train car of mass 3m. The cars stick together in the collision. How does the speed of the connected cars compare to the initial speed v? How does the kinetic energy of the system after the collision compare to the initial kinetic energy? (Increase, equal, or decrease?)
Both will be less.
300
If the balls collide and stick together, what is the post collision speed of the balls?
0 m/s
300
How do you calculate the velocity of the center of mass?
Total system momentum/Total system mass
300
What is the impulse delivered over this graph?
60 N*s
400
How much momentum does a 25 g marble rolling at 2 m/s have?
0.05 kg m/s
400
The two blocks collide and stick together.
Calculate how much energy the blocks lose.
m0=10 kg, v0= 4 m/s
480 J
400
A 0.1 kg dart is thrown upwards into the bottom of a 1 kg wooden block, sticking to it. It hits the block travelling at 4 m/s. How high will the block/dart combo rise?
0.031 m or approx. 3 cm.
400
The following closed system collision occurs. What was the center of mass velocity before the collision.
1 m/s. Closed system, so center of mass velocity is the same.
400
Calculate the change in momentum for a 6 kg object.
- 18 kg*m/s
500
What is the total momentum of all objects in the universe?
Zero
500
Block X has 2 kg of mass. Find the mass of block Y.
6 kg
500
A 1 kg cart travelling at +4 m/s strikes a stationary 2kg cart. After the collision the 1 kg cart has a velocity of -1 m/s, and the 2 kg cart has a velocity of +2.5 m/s. PROVE whether the collision was elastic or not.
MUST show that Ki=/=Kf
500
A 1 kg object is at a position of 0.5 m, a 2 kg object is at a position of 1 m, and a 3 kg object is at a position of 2m. Calculate the center of mass for this system.
Xcom=1.42 m
500
Find the total change in momentum.
-3 kg*m/s