Question

A string along which waves can travel is 2.5 m long and has a mass of 300 g. The tension in the string is 72 N. What must be the frequency of traveling waves of amplitude 6.6 mm for the average power to be 68 W?

Answer 1

You know tension, mass/length, amplitude, power.
http://hyperphysics.phy-astr.gsu.edu/Hbase/Waves/powstr.html
The issue is what is wave velocity?

I see no indication that wave velocity can be determined from what is given. It would be helpful if wavelength were known, (f*Lambda=v), or v.

Answer 2

What about v=sqrt(tension/(mass/Length))?

Answer 3

you can use that.

Answer 4

I tried to use this...can you tell me if this is the wrong approach or please tell me what I am doing wrong as I keep arriving at the wrong answer.

I tried finding v=sqrt(t/u) where t is torque & u is density. I substituted u with mass/Length.

I used this value and sub'd into equation P=(1/2)uvw^2y^2 again subbing u with m/L. I got w=208.24

I used this answer to fond f=w/2pi

Answer 5

w^2= 2P/A^2 * sqrt (1/Tu)

I get not your answer. A= .06, u=.3/2.5, T= 250

Answer 6

Thank you, you are always a great help!

Answer 7

A is .006m, not .06, typo.