A 12-kg box is pushed at constant speed (the box is already moving at this constant speed at t=0 s and continues to do so even after the animation ends) as shown in the animati...A 12-kg box is pushed at constant speed (the box is already moving at this constant speed at t=0 s and continues to do so even after the animation ends) as shown in the animation (position is given in meters and time is given in seconds). Why is the work done by your hand on the cart not equal to the product of this force component [calculated in part (e)] and the displacement of the cart?