NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
A small sphere of mass m suspended by a thread is first taken aside so that the thread forms a right angle with the vertical and then released. The total acceleration of the sphere when it makes an angle θ with the vertical is
Options
- Ag 1 + 3 cos 2 θ
- Bg 1 + cos 2 θ
- Cg 1 + sin 2 θ
- Dg 1 + 3 sin 2 θ
Correct answer
A. g 1 + 3 cos 2 θ
Step-by-step solution
Between A and B, mgL cos θ = 1 2 mv B 2 ∴ v B 2 = 2 gL cos θ Now, a r = v B 2 L = 2 g cos θ and a t = g sin θ ∴ a = a t 2 + a r 2 = g 1 + 3 cos 2 θ