A child is sending pulses down a stretched rope at a rate of 2 pulses per second. The distance between the pulses is 5 meters. What is the speed of the wave?  

Expert Answers
gsenviro eNotes educator| Certified Educator

A wave is characterized by a few parameters, such as frequency, wavelength, amplitude, time period, etc. The frequency of a wave is equal to the number of full cycles or pulses per second. The unit of frequency is cycles per seconds or hertz (hz).

In this case, since the child sends down 2 pulses per second, frequency = 2 hz.

The wavelength of a wave is the distance between crests or troughs of two successive waves. In this case, the distance between the waves is given as 5 m and hence the wavelength = 5 m.

The speed of a wave is the product of frequency and wavelength.

Thus, wave speed = frequency x wavelength = 2 hz x 5 m = 10 m/s.

Thus, the speed of the wave created by the child is 10 m/s.

Hope this helps.