In the figure, a block sitting on a frictionless horizontal surface is attached to a rigid wall on the right through a spring (whose axis is horizontal). A bullet is shot at the block from the left and gets embedded in it, causing the block to move to the right, thus compressing the spring. (Assume the bullet is travelling perfectly horizontally, along the axis of the spring, before hitting the block). Which of the following are true?
A. The initial kinetic energy of the bullet is completely converted to spring potential energy when the spring reaches its maximal compression.
B. The initial momentum of the bullet is equal to the momentum of the bullet+block system just after the bullet enters the block.
C. Part of the momentum of the bullet+block system is lost during the collision (i.e. before the spring-compression starts).
D. Part of the energy of the bullet+block system is ”lost” (no longer present as macroscopic kinetic energy) during the collision, before the spring-compression starts.
E. If we are given the masses of the block and the bullet, the initial speed of the bullet and the spring constant, it is possible to find the maximum compression of the spring.
1. A, E
2. A, B, D
3. B, D
4. A, B
5. A, C
7. B, D, E
8. A, C, E
9. A, B, E
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Collisions with Springs concept. You can view video lessons to learn Collisions with Springs. Or if you need more Collisions with Springs practice, you can also practice Collisions with Springs practice problems.
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