What is the work that must be done to increase the velocity of a bike that weighs 200 kg from 20 m/s to 30 m/s.
Work done = Change in kinetic energy. \begin{gathered}initial \: ke \: = \frac{1}{2} m {v}^{2} \\ = \frac{1}{2} \times 200 \times {20}^{2} \\ = 40000 \: joules\end{gathered}initialke=21mv2=21×200×202=40000joules finalke=21mv2=21×200×302=90000joules Therefore, By work-energy theorem, Work done= Change in kinetic energy =final KE - initial KE =50,000 J
