Physics help!? ASAP PLEASE?

Question

A 1.26 block is attached to a horizontal spring with spring constant 2800 . The block is at rest on a frictionless surface. A 12 bullet is fired into the block, in the face opposite the spring, and sticks.

What was the bullet's speed if the subsequent oscillations have an amplitude of 13.6 cm?

Could you determine the bullet’s speed by measuring the oscillation frequency?

Thanks!!

Answer 1

EWWEEEE. I hate mechanics questions with both momentum and oscillations.

However, I would like to mention that you need units. Your masses don't have units, and neither does your spring constant.

I would work backward from the oscillations part (which I completely forgot how to do) and then find the speed of the block when the bullet first hit it. Then, I would use conservation of momentum to find the speed of the bullet. (inelastic collision)