Name:__________________
Conservation of Momentum Problems
Do your work on another page!!! Assume that the sum of any external forces acting on the
system is zero. Note: The arrows are just supposed to show the direction of the car’s movement.
They do not represent the magnitude of the velocity.
1) Find the final velocity of the car on the right hand side.
Before the
V = 3 m/s
collision
V = -3 m/s
1 kg
1 kg
After the
collision
V= ?
V = -2 m/s
1 kg
1 kg
2) Find the final velocity of the car on the right hand side.
Before the
V = 2 m/s
collision
V = -2 m/s
1 kg
After the
collision
2 kg
V = -1 m/s
V= ?
1 kg
2 kg
3) After the collision, the two cars stick together. Find the final velocity of the two cars.
Before the
V=0
V = 2 m/s
collision
1 kg
2 kg
After the
collision
V= ?
1 kg
2 kg
4) After the collision, the two cars stick together. Find the initial velocity of the car on the right
hand side.
Before the
V = 3 m/s
collision
V= ?
1 kg
1 kg
After the
collision
V = 2 m/s
1 kg
1 kg
5) Two carts are at rest with a spring in between them. The spring is released. Find the mass of
the cart on the right hand side.
Before the
spring is
V = 0 m/s
released
2 kg
After the
spring is
released
V = -2 m/s
? kg
V = 0.5 m/s
2 kg
? kg
6) A cart is moving at a constant speed when a frog falls straight down onto the cart and sticks.
The frog had no horizontal velocity before landing in the cart. Find the velocity of the cart and
frog.
Before the
Frog
V = 3 m/s
frog falls
onto the cart
1 kg
After the frog
falls onto the
cart
Frog
V= ?
1 kg
mfrog = 0.5 kg