Question

Certain force acting on a 20kg mass changes its velocity from 5 m per second to 2 metre per second claculate workdone

Answer 1

m=20kg

u=5m/s

v=2m/s

work done = change in kinetic energy

=1/2m(v^2-u^2)

=1/2×20(4-25)

=10(-21)

=-210 J