Conventional rim brakes on a bicycle apply an approximately 1-kN force at the rim of the wheel, some 60 cm in diameter. Disc brakes, which are becoming increasingly popular, apply roughly 4 kN near the outer edge of a 200-mm-diameter disc. Estimate the torques to determine which braking system exerts the greater torque and by approximately what factor?

Complete these sentences. if a roller coaster train has a potential energy of 1,500 j and a kinetic energy of 500 j as it starts to travel downhill, its total energy isj. once the roller coaster train gets closer to the bottom of the hill, its kinetic energy increases to 1,100 j, and its potential energy decreases to j. when the train reaches the bottom of the track and is traveling along the ground, its kinetic energy isj.