Question

A simple pendulum makes 15 oscillations in 30


seconds. What
is the time period and frequency of its oscillation?
NCERT Class VIII
Science - Exemplar Problems
Chapter 13. Sound

Answer 1

Hi Mate!!!

For 15 oscillation it takes 30 sec

For one oscillation Tme period = 30/15 = 2sec

Frequency = 1/ Time period

Frequency = (1/2)Sec^-1 = 0.5 Sec^-1


Have a great future ahead

Answer 2

1. Time period is the time needed to complete one oscillation. That means,

               Time Period = time/ no. of oscillations

                                    = 30 seconds/ 15 oscillations

                                    = 2 seconds per oscillation

               Time Period = 2 s

    2.Frequency is the number of oscillations per second. That means,

               Frequency = no. of oscillations/ time

                                  = 15 oscillations / 30 seconds

                                  = 0.5 oscillations per second

                Frequency = 0.5 Hz (hertz)

From above answers we can get below relationship,

                     Frequency = 1/Time Period