NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
A block starts moving up a fixed inclined plane of inclination 60 ∘ with a velocity of 20   ms - 1 and stops after 2 s . The approximate value of the coefficient of friction is [ g = 10   ms - 2 ]
Options
- A3
- B3 .3
- C0 .27
- D0 .33
Correct answer
C. 0 .27
Step-by-step solution
Retardation of the block is a = g sin θ + μ cos θ = 5 3 + μ v = u - a t = 0 ⇒ a = u t ⇒ 5 3 + μ = 20 2 ⇒ μ = 0 . 27