- #1

- 351

- 3

## Homework Statement

Suppose a block of Uranium and a block of Radium, both with edge length [itex] \lambda [/itex], are pushed to the head of an un-stretched spring (spring constant [itex] k [/itex], un-stretched length [itex] \delta _0 [/itex]). The combination, pushed [itex] \delta [/itex] farther, compresses the spring. Upon release, the combination accelerates in the opposite direction. At what point do the blocks separate from the spring (not from each other)? What is their velocity at this instant? Assume the left block is Radium and the right block is Uranium. [itex] \lambda = 10cm [/itex], [itex] \rho _{radium} = 5 \frac{g}{cm^{3}} [/itex], [itex] \rho _{uranium} = 19.1 \frac{g}{cm^{3}} [/itex], [itex] k = 2410 \frac{dyne}{cm} [/itex], [itex] \delta _0 = 30 cm [/itex], [itex] \delta = 10 cm [/itex].

## Homework Equations

## The Attempt at a Solution

I have to say I am sort of stumped on this problem. I know that I can find the volume of each of the two blocks (assuming that they are cubes) by cubing the edge length, certainly I'll need that information later on in the problem. I was thinking that perhaps conservation of energy would be one way to approach the problem, but I believe that the instructor meant for us to use Newton's Law (this is for Mechanics class and we are doing the Force/Acceleration unit). I have my free body diagrams for the blocks drawn (and can post them if it would help). I was sort of hoping that someone could push me in the right direction and hopefully from there I'll be able to figure it out. Any help is appreciated, thanks.

Last edited: