61) Two simple pendulums A and B have equal length, but their bobs weigh 50 gf and l00 gf respectively. What would be the ratio of their time periods ? Give reason for your answer.
Ratio of their time periods would be 1:1.
Time period of simple pendulum is not dependent on the mass of its bob.
62) Two simple pendulums A and B have length 1·0m and 4·0 m respectively at a certain place. Which pendulum will make more oscillations in 1 minute? Explain your answer.
Time period of A = Ta
and Time period of B = Tb
Ta / Tb =√(1/4) = ½
So Tb = 2 Ta
A will take half of the time taken by B to complete an oscillation.
So obviously pendulum A will make more oscillations in 1 minute.
63)A simple pendulum completes 40 oscillations in one minute. Find its (a) frequency, (b) time period.
In 60 seconds it makes 40 oscillations
In 1 sec it makes = 40/60 = 2/3 oscillation
So frequency = 2/3 per second = 0.67 Hz
Time period = 1/frequency = 3/2 = 1.5 seconds
Go back to the 101 problems set (class 9)
Problems Set – grade 9