On an airtrack, cart 1, of mass m, moves to the right with constant speed v o to
ID: 581467 • Letter: O
Question
On an airtrack, cart 1, of mass m, moves to the right with constant speed vo toward cart 2. Cart 2 has mass 4m and is initially at rest.
After the collision, cart 1 has reversed direction and moves to the left.
1. Match next to cart 1 one of the arrows shown below which best represents the velocity of cart 1 after the collision. Repeat for cart 2.
2. Is the magnitude of the change in momentum for cart 1 greater than, less than, or equal to the magnitude of the change in momentum for cart 2? Explain or show your calculations.
3. Discuss what is incorrect in the following statement:
“Cart 2 will move to the right after the collision, but it would move faster if cart 1 were to come to a stop, giving cart 2 all its momentum.”
Explanation / Answer
Here ,
1. after the collision , as cart 1 reverses it's direction
the speed after the collision will be lower than the initial velocity.
the correct arrow is E
2.
as the total momentum is conserved during the collision
the change in momentum of cart A + change in momentum of cart B = 0
change in momentum of cart A = - change in momentum of cart B
hence , the change in cart A is equal to change in momentum for cart 2.
3.
in the statement ,
as the change in momentum is more when cart A reverses it's direction.
hence , the statement is wrong about the cart A stopping