Highly selective Backlog Qs for JEE MainPhysicsOscillations
When a body of mass 8 ~kg is attached to a spring balance, the reading of the balance is 20 ~cm . Instead of 8 ~kg , if another body of mass M is suspended from the spring balance and is made to oscillate vertically, the time period of oscillation is 5 ~s , then the value of M is (Acceleration due to gravity =10 ~ms ⁻² )
Options
- A4 ~kg
- B6 ~kg
- C8 ~kg
- D9 ~kg
Correct answer
A. 4 ~kg
Step-by-step solution
Mass of body, m =8 ~kg Period of oscillation, T = 5 ~s Reading of the balance, x=20 ~cm =0.2 ~m For mass 8 ~kg mg = kx k = mg x = 8 10 0.2 =400 ~N / m For mass M aligned & ^2= k M & M= k T^2 4 ^2 ( = 2 T ) & = 400 ^2 4 ^2 =4 ~kg aligned