Question

the time period of a simple pendulum ,that takes 42 seconds to complete 20 oscillations,equal to 2.1 seconds. True or False???

Answer 1

No. of oscillations completed by the pendulum= 42 

Time taken to complete 42 oscillation= 20 seconds 

Time period= No. of oscillations completed/Time taken 

Time period= 42/20 

= 21/10 (cancelled by 2) 

= 2.1 

Time period= 2.1 seconds

Answer 2

Given :

Time taken to complete 20 oscillations = 42 seconds

To Find :

Whether time period of oscillation is 2.1 sec or not.

Solution :

The time period of oscillation is defined as the time taken by the simple pendulum to complete one oscillation.

We are required to find the time period of a pendulum which takes 42 seconds to complete 20 oscillation.

Time taken to complete 20 oscillations = 42 seconds

Time taken to complete 1 oscillation =  $\frac{42}{20}$ seconds

                                                            =  2.1 seconds

Therefore, the Time Period of oscillation of simple pendulum is found to be 2.1 seconds.

Hence, it is True.