Question

A plastic float is attached to a fishing rope and describes 11 complete oscillations every 8 seconds. What is the wavelength if a single wave takes 4.21 seconds to travel a distance of 12 m?

 A rope of 3.2 m is being applied with a tensile force of 180 N and maintains a transverse wave speed of 190 m/s. Which mass does the rope have?

Answer 1

1. The  wavelength

$$\lambda=v*T\\ =(12\:\rm m/4.21\: s)*(8\:\rm s/11)=2.07\:\rm m$$

2. The speed of the wave

$$v=\sqrt{Tl/m}$$

So, the mass of the rope

$$m=Tl/v^2\\ =180\:\rm N*3.2\: m/(190\:\rm m/s)^2=0.016\:\rm kg=16\: g$$