A person fishing from a pier observes that four wave crests pass by in 7.0s and estimates that the distance between two successive crests is 4.0m. The timing starts with the first crest and ends with the fourth. What is the speed of the wave?
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Distance between two successive crests is 4.0m; this is one wavelength, call it L
4 wave crest take 7 seconds therefore t wave crest take 3.5 seconds; this is known as the period of the wave, T.
The frequency of the wave , f is given by 1/T, so that freq. is 1/3.5 Hz or 0.285 Hz
f = v/L
v, the velocity of the wave is, v= f x L = 0.285 x 3.5 = 1m/s
v = 1 m/s
4 wave crest take 7 seconds therefore t wave crest take 3.5 seconds; this is known as the period of the wave, T.
The frequency of the wave , f is given by 1/T, so that freq. is 1/3.5 Hz or 0.285 Hz
f = v/L
v, the velocity of the wave is, v= f x L = 0.285 x 3.5 = 1m/s
v = 1 m/s