NTA Abhyas JEE Main2020PhysicsWork, Power and EnergyPractice
A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is:
Options
- Am k 2 t − 1 2
- Bm k t - 1 2
- C2 m k t - 1 2
- D1 2 m k t - 1 2
Correct answer
A. m k 2 t − 1 2
Step-by-step solution
F v = c o n s t a n t = k m d v d t v = k ∫ v d v = ∫ k m d t v 2 2 = k m t v = 2 k m t F = m d v d t = m 2 k m 1 2 t - 1 2 = m k 2 t - 1 2