1. The problem statement, all variables and given/known data We did this roller coaster lab where we had a metal marble roll up and down this roller coaster track. One of the questions he asked us was "is energy "missing?" explain where it went." I know friction takes some of it, but im not good at wording it right to sound good. Help?? 2. Relevant equations PE= M*g*height KE= 1/2mv^2 3. The attempt at a solution I know it has to do with friction taking away some of it, but i need to make it sound good!