# Homework Help: Kinetic Energy Question

1. Nov 4, 2009

### Chuck Norris

1. The problem statement, all variables and given/known data
Say your potential energy at the top of a hill is 7,350 J. At the bottom of the hill wouldn't the kinetic energy then be 7,350 J?

2. Relevant equations

N/A

3. The attempt at a solution

N/A

2. Nov 4, 2009

### cepheid

Staff Emeritus
Hi Chuck Norris,

Assuming only conservative forces (like gravity) act on the object, then yes, mechanical energy will be conserved, and all of the potential energy at the top of the hill will have been converted into kinetic energy at the bottom of the hill. However, if there are non-conservative forces, such as friction, then some of the potential energy will be wasted and not all of it will be converted into energy of motion.

3. Nov 4, 2009

### Chuck Norris

Ok thanks that is what I thought. In the original question is says if friction can be ignored. So I believe that we are acting as if there is no friction involved. Thanks for your help.