Question
A source of sound produces 20 compressions and 20 rarefactions in 0.2 seconds. The distance between compression and the consecutive rarefaction is 50 cm. Find the wavelength, frequency and time period of the wave. [Ans. 100 cm, 100 Hz, 0.01 sec.]
Answer
Given:
Number of compressions = 20
Number of rarefactions = 20
Time taken = 0.2 seconds
Distance between compression and rarefaction = 50 cm
Wavelength = Distance between two consecutive compression
= 50 cm × 2 = 100 cm
Frequency = Total\ No.\ of\ oscillation \over Time
= 20 \over 0.2
= 100 Hz
Time period = 1 \over Frequency
= 1 \over 100
= 0.01 seconds
Therefore, the wavelength is 100 cm (0.5 m), the frequency is 100 Hz, and the time period is 0.01 seconds.
