BITSAT2018PhysicsOscillationsActual
The bob of simple pendulum is a spherical hollow ball filled with water. A plugged hole near the bottom of the oscillating bob get suddenly unplugged. During observation, till water is coming out, the time period of oscillation would
Options
- Afirst increase and then decrease to the original value
- Bfirst decrease and then increase to the original value
- Cremain unchanged
- Dincrease towards a saturation value
Correct answer
A. first increase and then decrease to the original value
Step-by-step solution
The bob filled completely with water has its centre of mass at its centre. The time period of oscillation is T = 2 π l g As the water starts coming out of the bob, its centre of mass shifts vertically downward and as a result, effective length of the pendulum increases and hence its period also increases. When the bob is empty, again its centre of mass appears at its centre and as a result, the period of oscillation again reaches to its original value.