Answer :
The distance between the 1st crest and 2nd crest is called wavelength. Hence 2 cm is the wavelength.
i suppose there is some thing missing in the question. Perhaps the 15 crests and 15 troughs are produced in 1 second.
Hence frequency then in that case is -- 15 per second or 15 Hertz.
the speed of the wave is v = frequency * wavelength
= 2 cm * 15 Hz = 30 cm/sec
i suppose there is some thing missing in the question. Perhaps the 15 crests and 15 troughs are produced in 1 second.
Hence frequency then in that case is -- 15 per second or 15 Hertz.
the speed of the wave is v = frequency * wavelength
= 2 cm * 15 Hz = 30 cm/sec