Answer to Question #221962 in Physics for caleb villarreal

Question

1. When you use a slingshot to launch a rock you stretch the rubber band storing potential energy. If you stretched the rubber band so that it had 130J of potential energy, with how much kinetic energy will the rock leave the slingshot if it loses 11J to heat & sound? 

 

Answer 1

Without the energy loss, all 130J of potential energy will be converted to the kinetic energy according to the enegry conservation law. But because of loss, the final kinetic enegy will be 11J less. Thus, obtain:

$$E_k = 130J - 11J = 119J$$

Answer. 119 J.