A phone cord is 4.75 m long. The cord has a mass of 0.200 kg. A transverse wave pulse is produced by plucking one end of the taut cord. The pulse makes four trips down and back along the cord in 0.900 s. What is the tension in the cord?

1 answer

The speed of the wave is 8*4.75 m/0.9 s
= 42.2 m/s

The lineal density of the cord is
s = 0.042 kg/m

The wave speed is sqrt(T/s)= 42.2

Solve for the tension, T