NTA Abhyas JEE Main2020PhysicsWork, Power and EnergyPractice
A particle starts with speed v 0 from x = 0 along x -axis with retardation proportional to the square of its displacement. Work done by the force acting on the particle is proportional to
Options
- Ax 5 2
- Bx 3
- Ce x
- Dx 2
Correct answer
B. x 3
Step-by-step solution
Given a = - Kx 2 or – v dv dx = x 2 integrating both sides – 1 2 v 2 – v 0 2 = x 3 3 Now, using work-energy theorem W = ∆ KE W   ∝   x 3