A cart of mass 20kg, initially at rest, is pushed with a net force of 40N on a flat surface. If the cart is pushed 5m, what is the final KE? What is the final velocity? (Assume no heat loss) Basically I understand to use: W = F x d to find out the work done, but where does the mass of the cart come into play? Also, if the cart only goes 5m, how can I find the velocity?