Q77 of 123 Page 255

A pendulum oscillates 40 times in 4 seconds. Calculate its

(i) time-period, and


(ii) frequency.


Can we hear the sound produced by the oscillations of this pendulum? Give reason for your answer.

Frequency = 40 vibration/ 4 seconds = 10 Hz


Thus, time period = 1/f = 1/10 = 0.1 seconds.


No, we cannot hear because the audible human range is from 20Hz to 20,000 Hz.


More from this chapter

All 123 →
77

What is meant by the 'time-period' of a vibrating object? State its unit.

 77

Define 'frequency' of a vibrating object. Name the unit in which frequency is measured.

 78

Draw a neat and labelled diagram of the human ear. Explain its working.

 79

What is noise? Give two examples of sounds which are considered noise.