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3 years ago

A sound wave is direct at a wall. In 20 seconds, 200 wave cycles hit the wall.

Physics

1 answer:

Tems11 [23]3 years ago

7 0

Answer:

Frequency=10 Hz

Period=0.1 s

Explanation:

Frequency of a wave is the number of complete cycles per unit time. Usually, frequency is cycles per second, with unit as Heartz

Given cycles of the wave as 200 and time as 20 seconds

Frequency=200÷20=10 cycles per second

Therefore, frequency is 10 Hz

Period is usually the reviprocal of frequency hence reciprocal of 10 Hz will be 1/10=0.1 s

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Answer:

a. B = 0.20T

b. u = 17230.6 J/m³

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Explanation:

a. In order to calculate the magnetic field in the solenoid you use the following formula:

$B=\frac{\mu_o n i}{L}$ (1)

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$u=\frac{B^2}{2\mu_o}=\frac{(0.20T)^2}{2(4\pi*10^{-7}T/A)}=17230.6\frac{J}{m^3}$

The energy density is 17230.6 J/m³

c. The total energy contained in the solenoid is:

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V is the volume of the solenoid and is calculated by assuming the solenoid as a perfect cylinder:

$V=AL$

A: cross-sectional area of the solenoid = 0.550 cm^2 = 5.5*10^-5m^2

$V=(5.5*10^{-5}m^2)(0.25m)=1.375*10^{-5}m^3$

Then, the energy contained in the solenoid is:

$E=(17230.6J/m^3)(1.375*10^{-5}m^3)=0.236J$

The energy contained is 0.236J

d. The inductance of the solenoid is calculated as follow:

$L=\frac{\mu_o N^2 A}{L}=\frac{(4\pi*10^{-7}T/A)(460)^2(5.5*10^{-5}m^2)}{0.25m}\\\\L=5.84*10^{-5}H$

The inductance of the solenoid is 5.84*10^-5 H

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