Highly selective Backlog Qs for JEE MainPhysicsLaws of Motion
As shown in the figure, two particles, each of mass ' m ' tied at the ends of a light string of length 2 a are kept on a frictionless horizontal surface. When the mid point ( P ) of the string is pulled vertically upwards with a small but constant force F , the particles move towards each other on the surface. Magnitude of acceleration of each particle, when the separation between them becomes 2 x is
Options
- AF 2 m a a 2 - x 2
- BF 2 m x a 2 - x 2
- CF 2 m x a
- DF 2 m a 2 - x 2 x
Correct answer
B. F 2 m x a 2 - x 2
Step-by-step solution
From the above diagram, tan θ = a 2 - x 2 x , 2 T sin θ = F and T cos θ = m a from the above equations, a = F cot θ 2 m ⇒ a = F 2 m 1 tan θ = F 2 m x a 2 - x 2