What is the relationship between potential and kinetic energy?

[Chann]

I need help with this question.

An 8.0 kg bowling ball is rolled from the top of a hill. At the bottom of the hill, the ball is moving at a speed of 7.42m/s. What is the height of the hill?

Im trying to use h=PE/mg but i can't get PE with the given at top. May you guys help ? Please and thank youWait I think I got it I need a confirmation does KE=Pe ?

 

[kk727]

Wait I think I got it I need a confirmation does KE=Pe ?

Yes, since energy is always conserved, your PE and KE at any given point should always add up to the same number. For example, if you're at the top of a hill and not moving, you have only potential energy; that number would all be converted to kinetic energy if you were at the bottom of the hill. The bottom line is, you generally always have the same amount of energy (without taking things like friction into account).