KCET2013PhysicsWork, Power and Energy
A truck accelerates from speed v to 2 v . Work done in during this is
Options
- Athree times as the work done in accelerating it from rest to v
- Bsame as the work done in accelerating it from rest to V
- Cfour times as the work done in accelerating it from rest to v
- Dless than the work done in accelerating it from rest to v
Correct answer
A. three times as the work done in accelerating it from rest to v
Step-by-step solution
Work done to accelerate from 0 to v is, W₁= 1 2 m v² Work done to accelerate from v to 2 v is, aligned W₂ &= 1 2 m(2 v)² W &=W₂-W₁= 1 2 m(2 v)²- 1 2 m v² & 4 W₁-W₁=3 W₁ aligned