NTA Abhyas JEE Main2020PhysicsLaws of MotionPractice
A stone of mass 1 kg tied to a light inextensible string of length L = 1 0 3 m is whirling in a circular path of the radius L in the vertical plane. If the ratio of the maximum tension to the minimum tension in the string is 4 . What is the speed (in m s - 1 ) of stone at the highest point of the circle? (Take g = 1 0 m s - 2 )
Correct answer
10
Step-by-step solution
mg + T A = mv A 2 L T B - mg = mv B 2 L T B T A = mv B 2 L + mg mv A 2 L - mg = 4 4 v A 2 - v B 2 = 5 gL By energy conservation 1 2 m v B 2 = 1 2 m v A 2 + m g h A v B 2 = v A 2 + 4 gL v A 2 = 3 gL = 3 × 10 × 1 0 3 v A = 10 m s - 1