Tension, pulse, and time

1. Jan 15, 2008

astro_kat

1. The problem statement, all variables and given/known data
a cord of mass 0.65 Kg is stretched between two supports 28 m apart, The tension of the cord is 150 N, how long will it take a pulse to go from one end to the other?

2. Relevant equations
ok, so I really know is: speed of wave=frequency*wavelength....

3. The attempt at a solution
I really have no clue, I know the distance, with the speed I can solve for frequency, but I don't know how to find time elapsed.... can anyone help me, I have no clue how to use tension in this problem!

2. Jan 15, 2008

rock.freak667

the speed of a wave traveling through the string would be

$$v=\sqrt{\frac{T}{\mu}}$$

where $\mu$ is the mass per unit length

3. Jan 15, 2008

astro_kat

oh, cool, yeah i remember seeing that equation somewhere before... right so:
v= (150/(0.65Kg/28m))^.5

take that number, given the length of the cord I can solve for time

4. Jan 15, 2008

rock.freak667

That should work,yes