A block of mass m and height h slides without friction up a hill rise of height (3/2)h as shown. In order to make it to the top of the hill, the block must have a minimum initial speed of: Pe+Ke = Pe(f) + Ke(f) I tried figuring out what the velocity of the block would be if it had slid down the hill. I was assuming it would require that amount of velocity to go back up the hill (maybe I assumed wrong). The answer listed is (3gh)^1/2 However my answer was (2gh)^1/2. The block has a height h but I don't understand why the size of the block should matter. Nor do I have any idea of how to incorporate that fact into my equation, please help.