Solved: Pulse Wave Problem - Speed of the Crest in m/s

[bricker9236]

Homework Statement

A string of length l = 5 m weighs M = 10 kg . A pulse wave is traveling along the string. What is the speed v of the crest of the pulse, in the uint of m/s , if the tension of the string F is 200 N ?

Homework Equations

v= sqrt F/u
u= m/L

HELP: We can obtain an expression for the wave speed by analyzing the forces acting a string of length l and mass M. Do you recall the resulting relation between the speed of the wave and the tension and the linear density?

HELP: ...Get the density by defination and then use above equation.

The Attempt at a Solution

I tried importing the numbers into the equation what I thought was the equation the HELP statement suggested.. and i got

v=sqrt 200/(10/15) = 17.320 ... is there something else i should be doing because this answer was wrong but i thought for sure i was doing it correct.

 

[kuruman]

The length of the string is 5 m. Where did you get 15 m?