A cart, initially at rest, slides down a frictionless ramp onto a horizontal frictionless surface which is a distance h below the original position of the cart. It then collides with the free end of a relaxed horizontal spring, the other end of which is fixed to a wall. As a result the spring compresses a distance D. Suppose now the initial height is changed to 2h. How far will the spring now compress? A) sqrt(2)D B) 2D C) 4D ------ Initially: mgh = 0.5 k D^2 Suppose: mg(2h) = 0.5 k (2D)^2 So... the spring will now compress 4D. Is this correct?