Question

work done in moving a body of mass m to increase its velocity from 5ms to 8ms is​

Answer 1

w=F*S

w=m*v^2

w=m(8^2-5^2)

w=39m

Answer 2

Given,

Mass of the object = m

Initial velocity 'u'    = 5 m/s

Final velocity  'v'    = 8 m/s

To find,

Work done in moving a body

Solution,

Work done in moving a body of mass m = change in kinetic energy

    Kinetic Energy = 1/2 m(v²-u²)

                              = 1/2 m (64-25)

                              = 1/2 m (39)

                              = 19.5m Joules

Hence, work done in moving a body of mass m to increase its velocity from 5 m/s to 8 m/s is 19.5m Joules.