I have a question. If a put a marble at the top of a ramp, will the angle that ramp makes with the horizontal affect the velocity of the marble when it arrives at the bottom of the ramp? I am suspecting no, since the gravitation potential energy does not change as we change the angle of the ramp, so when the marble arrives at the bottom, all of that potential energy must be kinetic and thus the velocity must be the same. I think that changing the angle will only affect how long it takes to reach the bottom, since all we're doing ins modifying the parallel force component. Is all of this correct?