How Do You Calculate the Oscillation Frequency of an Engine Block on a Cable?

[Rubidium]

1. Homework Statement
A winch cable has a cross sectional area of 1.5 cm^2 and a length of 2.5 m. Young's modulus for the cable is 150 GN/m^2. A 950-kg engine block is hung from the end of the cable.
(a) By what length does the cable stretch?
(b) If we treat the cable as a piece of string, what is the oscillation frequency of the engine block at the end of the cable?




2. Homework Equations
f=1/T=\omega/2\pi




3. The Attempt at a Solution
For (a) I used Young's modulus and found that the cable stretches 0.104 cm.
For (b) I don't know how to go about finding the frequency.
Thanks.

 

[dwintz02]

Think of the cable as a spring and the engine as a mass on the end of a spring. When the cable stretches it will stretch past its equilibrium point and then compress back up, then stretch back down...etc. Given that the cable is behaving like a spring, how can you relate Young's modulus to the spring constant (usually k)?