Consider a 200-kg cart starting from rest at point A, which is 6.0m above the ground as shown in the figure below. The cart follows the roller-coaster tracks from point A to point B, where point B is 3.2m above the ground. Assuming the potential energy of the system is zero at the ground level and rounding off the number to three significant figures, the speed of the cart at point B is m/s. If 3 kJ of the total mechanical energy is lost due to friction between points A and B, the speed of the cart at point B is m/s.