A transverse wave on a rope is given by y(x,t)=(0.750cm)cos(π[(0.400cm−1)x+(250s−1)t]).Find the average power of this wave.

Respuesta :

Answer:

The average power of this wave is 5.42 Watts.

Explanation:

The transverse wave on a rope is given by :

[tex]y(x,t)=0.75\ cos(\pi [(0.4)x+250t])[/tex]

The general equation of the transverse wave is :

[tex]y=A\ cos(kx+\omega t)[/tex]

Let the mass per unit length of the rope is 0.0500 kg/m.

The average power of this wave is given by :

[tex]P=\dfrac{1}{2}\mu \omega^2A^2 v[/tex]

Where

[tex]\mu[/tex] is the linear mass density, [tex]\mu=0.05\ kg/m[/tex]

[tex]\omega=250\pi = 785.39\ rad/s[/tex]

A =  0.75 cm = 0.0075 m

Propagation constant,

[tex]k=0.4\pi[/tex]

[tex]\dfrac{2\pi}{\lambda}=0.4\pi[/tex]

[tex]\lambda=5\ cm=0.05\ m[/tex]

Angular velocity,

[tex]2\pi f=250\pi[/tex]

f = 125 Hz

Velocity,

[tex]v=f\lambda[/tex]

[tex]v=125\times 0.05=6.25\ m/s[/tex]

Average power of the wave is :

[tex]P=\dfrac{1}{2}\mu \omega^2A^2 v[/tex]

[tex]P=\dfrac{1}{2}\times 0.05\times (785.39)^2 \times (0.0075)^2\times 6.25[/tex]

P = 5.42 Watts

So, the average power of this wave is 5.42 Watts. Hence, this is the required solution.