Hello, 1. The problem statement, all variables and given/known data A spherical continuous ball is sliding with a constant velocity v along a frictionless lane. Thereafter it enters an inclined surface (the angle between the surface and the horizontal plane is α) with the coeﬃcient of friction µ between the ball and the surface. 2. Relevant equations Find the maximal height it may reach if it is known that before full stop the ball was rolling. 3. The attempt at a solution I solved it using energies but i get an extra dependence on velocity when the ball starts rolling, and my professor told me to repeat the exercice using torque, where the solution is nicer. I divided the motion in two parts: 1-First the ball is sliding, when it starts going up the ramp the frictional force causes it to start rotating and lose velocity until v(t1)=wR (rolling condition). 2-From rolling until it stops at v(t2)=0 1: I use v(t1)=v(0)+at => (wR)=v(0)+at, but a depends on t as well, so I don't know how to continue.