Suppose you are testing a new amusement park roller coaster with an empty car with a mass of 100 kg. One part of the track is a vertical loop with a radius of 12.0 m. At the bottom of the loop (point A), the car has a speed of 25.0 m/s and at the top of the loop (point B), it has a speed of 8.00 m/s. As the car rolls from point A to point B, how much work is done by friction? Use 9.81 m/s2 for the acceleration due to gravity.