A cart begins from the top of a hill, originally at rest, and then travels down the slope. The hill has a height of 15 meters and a slope of 36 meters. The cart's mass is 6 kg and its final velocity becomes 4 m/s when the cart finally travels to the bottom of the slope. Calculate the "work" that's is being done against the friction. If anyone can provide a detailed response with appropriate steps, I would it appreciate it.