1. An industrial beam is bent 135.2m by an applied force of 1.75 x 10^3n
a) Find the beam's spring constant.
b) calculate the beam's elastic potential energy.
2. How long would it take a person to hear their echo from a cliff 193m away if the air temperature was 16.7 c?

1.a) Use F = ke?
b) Use E_p = \frac{Fe^2}{2} ?

2. Find the speed of sound in air at such a temperature then use d = st?

1.a) Use F = ke?


Right, where e = the beam's deflection.



b) Use E_p = \frac{Fe^2}{2} ?


Not quite. Use E = \frac 1 2 k e^2. Recall that the units for energy is N-m.



2. Find the speed of sound in air at such a temperature then use d = st?
Agreed.

Oops, I meant to type k... otherwise, it'd be Fe/2. :o