NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
At the instant t = 0, a force F = k t ( k is a constant) acts on a small body of mass m resting on a smooth horizontal surface. The time, when the body leaves the surface is
Options
- Am g k sin ⁡ α
- Bk   sin   α m g
- Cm g   sin ⁡ α k
- Dm g k sin α
Correct answer
D. m g k sin α
Step-by-step solution
N + F sin α = m g The body leaves the surface when the normal reaction on it becomes zero. N = 0 ⇒ k t sin α = m g t = m g k sin α