A body of mass 250g moving on a horizontal rough table.What is the work done if a frictional force is acting on it and brings the body to rest which was initially moving with a speed of 40cm/s?

Given that,

 

Mass of the body m = 250 g

Initial velosity u = 40 m/s

Final velosity  v = 0 m/s   (Because body comes at rest)

 

Work done = change in kinetic energy

 

 

Here negative sign denotes the work done in opposite direction of the motion.