A cart loaded with bricks has a total mass of 8.9 kg and is pulled at constant speed by a rope. The rope is inclined at 28 ◦ above the horizontal and the cart moves 8.1 m on a horizontal floor. The coefficient of kinetic friction between ground and cart is 0.7 . The acceleration of gravity is 9.8 m/s 2 . How much work is done on the cart by the rope? Answer in units of kJ.