MHT CET202122 Sep 2021Morning ShiftPhysicsWork, Power and EnergyActual
A car of mass ' m ' moving with velocity ' u ' on a straight road in a straight line, doubles its velocity in time t . the power delivered by the engine of a car for doubling the velocity is
Options
- A3 mu ^2 2 t
- Bmu ^2 2 t
- C2 mu ^2 t
- D3 mu ^2 t
Correct answer
A. 3 mu ^2 2 t
Step-by-step solution
Initial kinetic energy k ₁= 1 2 mu ^2 Final kinetic energy k ₂= 1 2 mu ₂^2= 1 2 ~m (2 u )^2= 1 2 (4 mu ^2 ) k ₂- k ₁= 3 2 mu ^2 Change in K.E. is work done Power, P = workdone t = 3 mu ^2 2 t