A crate of fruit with a mass of 30.0kg and a specific heat capacity of 3700J/(kg%u22C5K) slides 8.90m down a ramp inclined at an angle of 36.2degrees below the horizontal.
If the crate was at rest at the top of the incline and has a speed of 2.20m/s at the bottom, how much work Wf was done on the crate by friction?
Use 9.81m/s2 for the acceleration due to gravity and express your answer in joules.