Question

A strong transverse pulse created at one end of a string is observed to complete 5 up and down journey along its length before fading out. The length of the string is 8m and the pulse takes 20 seconds to complete these journeys. What is the speed of the pulse through the string?

Answer 1

Distance trvelled in one complete journey, d = 8+8 = 16 m
Dsitance travelled in 5 return journeys, D = 5*d = 5*16 = 80 m
Time taken, t = 20 seconds
Speed of the pulse :
v = D/t
= 80/20
= 4 m/s
Hence, the speed of the pulse through the string is 4 m/s.