A moving truck has momentum. If it moves four times as fast, its momentum is as much. Two carts, one three times as heavy as the other, move down a hill at the same speed. Compared to the lighter cart, the momentum of the heavier cart is as much. 3 A bus is traveling at highway speeds when the momentum of an unlucky bug is suddenly changed as it splatters into the bus' front window. a. Compared to the force that acts on the bug, how much force acts on the bus?