7. A hockey puck of mass 0.20 kg is traveling along an increasingly rough surface, which can be described by a spatially dependent coefficient of kinetic friction, µ = 0.1

+ 0.02 x, where x is in meters. Find the work done by the kinetic frictional force on the hockey puck when it has moved in the x direction... [6 pt] a. ..from x =0 m to x = 2.5 m. b. .from x = 4.0 m to x = 8.0 m. c. If the puck was initially traveling at 4.0 m/s, at what distance from x = 0 m would the puck come to a stop?

Fig: 1

Fig: 2

Fig: 3

Fig: 4