You push a box of mass 15 kg with your car up to an icy hill slope of irregular shape to a height 4.7 m. The box has a speed 12.2 m/s when it starts up the hill, the same time that you brake. It then rises up to the top (with no friction) with a horizontal lip before immediately falling off a sheer cliff to the ground (with no drag). (a) What is the speed of the box at the top of the hill? :l (b) What is the direction (unit vector) of the box's velocity just before hitting the ground? 0 = '7 + l '2