Most Important Selected Qs for JEE AdvancedPhysicsOscillations
A bob of mass 2 m hangs by a string attached to the block of mass m of a spring block system. The whole arrangement is in a state of equilibrium. The bob of mass 2 m is pulled down slowly by a distance x₀ and released.
Options
- AFor x ₀= 3 mg k maximum tension in string is 4 mg
- BFor x ₀ 3 mg k , minimum tension in string is mg
- CFrequency of oscillation of system is 1 2 k 3 ~m , for all non-zero values of x ₀
- DThe motion will remain simple harmonic for x ₀ 3 mg k
Correct answer
D. The motion will remain simple harmonic for x ₀ 3 mg k
Step-by-step solution
aligned & (A) kx =3 mg ; equ ^ n . & k ( x + x ₀ )- T - mg = ma ....(1) & ~T -2 mg =2 ma ....(2) aligned On solving, aligned & T = 2 ~m 3 k ( x + x ₀ ) for x ₀= 3 mg k & ~T =4 mg aligned (D) If x ₀= 3 mg k If x₀ 3 m g k then string will become lack when ' m ' comes to rest at top most extreme possible.]