JEE Main2012PhysicsWork, Power and EnergyActual
A particle gets displaced by r =(2 i +3 j +4 k ) m under the action of a force F =(7 i +4 j +3 k ) . The change in its kinetic energy is
Options
- A38 ~J
- B70 ~J
- C52.5 ~J
- D126 ~J
Correct answer
A. 38 ~J
Step-by-step solution
According to work-energy theorem, Change in kinetic energy = work done = F r =(7 i +4 j +3 k ) (2 i +3 j +4 k )=14+12+12=38 ~J