Some one me with part B. (Simple Harmonic Motion)

[bochai]

Simple Harmonic Motion

A block of mass M = 10 kg is hanging, at rest, from a spring with a force constant of 250 N/m. There is also a very small penny sitting on top of the block. (Note: The penny is not stuck to the block and can leave the surface of the block.) The block is now pulled down a distance of 0.8 m held there and then released. Note: Assume that the mass of penny << mass of bock

Part A
Answer the following five questions by analytical means (i.e. math methods). Assume that Simple Harmonic Motion holds.
1) angular frequency of the system
2) amplitude of vibration
3) period of vibration
4) linear frequency of vibration
5) maximum acceleration the block experiences
Note: Do not consider the penny for the above calculations.

Part B
Now considering the penny as part of the system but assuming the mass of the penny is so small compared to the block that the Simple Harmonic Motion of the block is not affected by the penny.
Answer the following four questions by analytical means (i.e. math methods).
6) Why will the penny leave the surface of the block? Explain.
7) At what time will the penny leave the surface of the block after the block is released?
8) At what position, x, will the block be when the penny leaves the surface?
9) What will be the speed of the block when the penny leaves the surface?

(Part A is easy, but I'm not sure how to approach part B)

 

[vanesch]

I'm moving this to the HW section.

BTW, you should show an effort for your solution there before people will help you (read the rules).

 

[Astronuc]

In part B, the penny is resting on the block.

What forces are acting on the penny, and what forces are acting on the block?

Also realize, the force of gravity is constant, but the spring force depends on the displacement from equilibrium.