Question

In a pond , ripples are sent and a floating object goes up and down 6 times in 15 sec . The

wave crests are 0.4 m apart. Calculate :-

(i) wavelength

(ii)frequency(f)

(iii)speed of sound wave (v)

(iv)period of the wave (T)​

Answer 1

Wavelength is defined as distance between two identical points on consecutive waves. i.e distance between two consecutive crests.

Therefore, Wavelength  = 0.4 m

Time period is defined as time taken to complete one oscillation.

According to question,

Time taken for 6 oscillations = 15 sec

Then, Time taken for 1 oscillation = 15 / 6 = 2.5 sec

Therefore, Time period = 2.5 sec

Frequency is defined as  number of oscillations per second.

Frequency is given as:

Frequency = 1 / time period

or, F = 1 / 2.5

or, F = 0.4 Hz

Therefore, Frequency = 0.4 Hz

And, Relation between Frequency, Wavelength and speed of sound wave is given as:

Speed of wave = freqeuncy * wavelength

or, Speed of wave = 0.4 * 0.4

or, Speed of sound wave ( v) = 0.16 m/s

Answer 2

Wavelength is defined as distance between two identical points on consecutive waves. i.e distance between two consecutive crests.

Therefore, Wavelength  = 0.4 m

Time period is defined as time taken to complete one oscillation.

According to question,

Time taken for 6 oscillations = 15 sec

Then, Time taken for 1 oscillation = 15 / 6 = 2.5 sec

Therefore, Time period = 2.5 sec

Frequency is defined as  number of oscillations per second.

Frequency is given as:

Frequency = 1 / time period

or, F = 1 / 2.5

or, F = 0.4 Hz

Therefore, Frequency = 0.4 Hz

And, Relation between Frequency, Wavelength and speed of sound wave is given as:

Speed of wave = freqeuncy * wavelength

or, Speed of wave = 0.4 * 0.4

or, Speed of sound wave ( v) = 0.16 m/s