Hi! I have some questions from a study guide in my physics class, and they give me the answer, but I have to show how to get the answer. I did most of them, but need help with these. Here is problem #8:

A 20 kg block of ice slides without friction down a long hill. The start of the hill is 7.5 m higher than the bottom of the hill, and the path traveled is 18.0 m. Find the speed of the block when it reaches the bottom of the hill. (12.1 m/s)

1 answer

mgh=mv²/2
v=sqrt(2gh)=...