Hi, If I have a ball at the top of a ramp, it will have rotational and translational kinetic energy as it begins moving. If the ramp was frictionless, just to confirm, would it be possible for the ball to rotate or would it just slide with the point of contact on the ramp fixed? Also, if there is friction and the ball is allowed to rotate, will the ball lose energy while it goes from the top of the ramp to the bottom? To my understanding, friction is a nonconservative force and will result in energy dissipated from the system (i.e. the ball). But in this case, if friction is necessary for the ball to rotate, would I have to account for a loss of energy term when trying to figure out the ball's position, speed, and acceleration as it moves on the ramp? In this case, is the energy loss through friction negligible? Would it ever not be negligible?