A cylindrical cork of uniform density floats in a liquid of density 1. If the cork is depressed slightly and released, it oscillates harmonically with time period T. If the same cork floats in another liquid of density 2, then the similar oscillation has time period 2T. The value of 2 / 1 is:
- 1/4
- 4
- 2
- 1/2
Answer
(1) 1/4
Solution
The restoring force for vertical oscillation of a floating cylinder is F = -A g y, which gives an effective spring constant k = A g.
The time period of oscillation is:
T = 2 mA g T 1
Therefore:
T1T2 = 2 1
Given T1 = T and T2 = 2T:
T2T = 2 1 12 = 2 1 2 1 = 14
Answer: (1)