Question

a force acting on a 20 kg mass changes it's velocity from 5 m/s to 2 m/s. what is the work done by the force​

Answer 1

Answer:

Work done will be equal to change in kinetic energy

$w \\ = \frac{1}{2} \times 20 \times {2}^{2} - \frac{1}{2} \times 20 \times {5}^{2} \\ \\ =10(4 - 25) \\ = - 210 \: j$