# Find tension required for wave speed?? PLEASE NEED FOR FINAL EXAM ON MONDAY?

14-38) The speed of a transverse wave on a string is 14 m/s when the tension is 4.0 N. What tension is required for the wave speed along the string to be 17 m/s? Answer in Newtons.

### 5 Answers

- AlgolLv 710 years agoFavorite Answer
You need the linear density of the string:

v = √[F/μ]

μ = F₁/v₁²

Then, force in the second case is:

F₂ = μv²

= (F₁/v₁²)v₂²

= [4.0N/(14m/s)²](17m/s)²

= 5.9N

Hope this helps.

- 10 years ago
The equation for calculating the speed of a wave on a string is:

speed = sqrt ( tension/density)

First calculate the density given the known speed and tension:

(speed * speed) = tension/density

density = tension/(speed * speed)

density = 4.0 / (14*14)

density = 0.020408 kg/m

Now we can solve for the tension required for a wave speed of 17 m/s:

tension = (speed * speed) * density

tension = (17*17) * 0.020408

tension = 5.897912 N

- SteveLv 710 years ago
u = √[T/µ] → T = u²*µ and T2/T1 = [u2²/u1²]*µ = µ*[17/14]² → T2 = 5.898 N

Source(s): University Physics, Sears & Zemansky, 1955 - How do you think about the answers? You can sign in to vote the answer.