A 12-pack of Omni-Cola (mass 4.30 kg) is initially at rest on a horizontal floor. It is then pushed in a straight line for 1.20 m by a trained dog that exerts a horizontal force with magnitude 36.0 N. Use the work-energy' theorem to find the final speed of the 12-pack if
(a) There is no friction between the 12-pack and the floor, and
(b) The coefficient of kinetic friction between the l2-pack and the floor is 0.30.