# 7. A wave described by the function below propagates in a string under a tension of 0.18 N.?

the answers are in the box, but i dont understand the work needed to find them. help would be greatly appreciated.

### 2 Answers

- NCSLv 72 months ago
I agree with the other poster for the answer to (a).

But the PARTICLE'S velocity is given by

v(x,t) = dy/dt = 2.4x10^-3m * 270rad/s * cos(36x - 270t)

v(x,t) = 0.648m/s * cos(36x - 270t)

which is a maximum when cos() = 1 --

max v = 0.648 m/s ◄

7.5 m/s is the WAVE'S velocity.

Hope this helps!

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- FiremanLv 72 months ago
Thus is a transverse harmonic wave traveling in the positive x-direction. Harmonic waves are sinusoidal waves. The displacement y of a particle in the medium is given as a function of x and t by

y(x,t) = Asin(kx - ωt)

Here k is the wave number, k = 2π/λ, and ω = 2πf is the angular frequency of the wave.

=>Thus v = ω/k

=>v = 270/36

=>v = 7.50 m/s

By v = √[T/µ]

=>v^2 = T/µ

=>µ = T/v^2 = 0.18/(7.50)^2 = 3.2 x 10^-3 kg/m OR 3.2 g/m

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