posted by Uris .
A 700# rock sits atop a 150 foot cliff.
1) If it is pushed off how much kinetic energy is in the rock just before it hits the ground?
2) How much potential energy does it have just before it hits the ground?
On 2 will I use the mgh formula? If so what height do I use?
On 1 , I think I use the formula 1/2mv^2, if that is correct what number do I plug in the v spot?