Physics HW#1

A 500 g block slides down a 20.0 incline at speed 3.0m/s. After the block has traveled 2.0m along the incline, its speed is 4.3 m/s. (a) After the block has slid 2.0m down the incline, by what amount has the thermal energy of the block-incline system changed? (b) What is the coefficient of kinetic friction between the block and the incline