Speed of a transverse on a pulley

[Andrew Jacobson]

Homework Statement

Hi, I encountered a problem whilst doing problems involving transverse waves. If somebody could give me a pointer I would appreciate it. The question is:

"One end of a horizontal rope is attached to a prong of an electrically driven tuning fork that vibrates the rope transversely at 120Hz. The other end passes over a pulley and supports a 1.50kg mass. The linear mass density of the rope is 0.055kg/m. What is the speed of a transverse wave on rope?"

The answer in the book is 16.3m/s.

Homework Equations

The Attempt at a Solution

If I'm honest I'm struggling to even start. I figure that you have to balance the forces, where the downward force would be 9.81*(1.5+0.055L)N where L is the length of the rope and perhaps you can relate that to the power of the tuning fork and work it out from there? A pointer would be lovely. Thanks.

 

[BvU]

Nah, there is an expression for the speed of a wave as a function of the tension in a rope. Find it (in your textbook or in your notes, for instance) and you're done.

Tuning fork power would have been provided if that was needed for the exercise. Pulley and weight only serve to get the tension.