Sound Waves Traveling Down a String

[eagles12]

Homework Statement

A brother and sister try to communicate with a string tied between two tin cans. If the string is 9.5m long, has a mass of 55g and is pulled taut with tension 6N, how much time does it take for a wave to travel from one end of the string to the other?

Homework Equations

v=√(F/M)
M=mass/length
t=d/v

The Attempt at a Solution

First, I converted 9.5m to 950cm and 55g to .055kg
I used these to find M=.055/950
M=5.7* 10^-5
I used F=6N and divided that by M, then took the square root and i got
v=321.96
then I divided 950 by 321.96 in order to get the time, and got
t=2.95 but this is incorrect.

 

[Doc Al]

First, I converted 9.5m to 950cm

Why? Meters is the units you want.