ok thanks for the explanation - it makes sense.da_willem said:There is no 'friction energy' part of the system. It is a dissipative power. Once energ is coverted in this 'friction energy' (ie heat, sound etc.) it is gone. So having less friction doesn't speed you up, absence of friction doesn't add energy to the motion. As said before, this only works for an applied force, even when the breaks are on.
but wouldn't the absence of friction decrease the decelerating force and therefore create an acceleration?
what about a curling stone that you slide over a carpet that is on an ice rink. what will happen when the rock hits the edge of the carpet and slides onto the ice? will it speed up or not?
is this situation similar?