Question

Two simple pendulums A and B have equal lengths, but their bobs weigh 50 gf and 100 gf, respectively. What would be the ratio of their time periods? Give reasons for your answer.

Answer 1

The ratio of their time periods would be 1:1 because the time period does not depend on the weight of the bob.

Answer 2

We know that the time period of the simple pendulum at a place is given by

T = `2πsqrt("l"/"g")` ........(i)

and this expression does not contain the weight of bob i.e. is independent of the weight of bob.
∴ Time period of both pendulums will be the same.
∴ Ratio of their time periods =1 : 1