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3 years ago

5

The volume control on a surround-sound amplifier is adjusted so the sound intensity level at the listening position increases fr

om 23 to 61 dB. What is the ratio of the final sound intensity to the original sound intensity?

1 answer:

amid [387]3 years ago

5 0

Answer:

Ratio will be $\frac{I_2}{I_1}=10^{3.8}=6309.5$

Explanation:

We have given that intensity level is increases from 23 dB to 61 dB

We know that level of intensity is given by

$i=10log\frac{I}{I_0}$

So $23=10log\frac{I_1}{I_0}$ ------eqn 1

And $61=10log\frac{I_2}{I_0}$ ------eqn 2

Subtracting eqn 1 from eqn 2

$61-23=10log\frac{I_2}{I_1}$

$3.8=log\frac{I_2}{I_1}$

$\frac{I_2}{I_1}=10^{3.8}=6309.5$

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An infinite sheet of charge, oriented perpendicular to the x-axis, passes through x = 0. It has a surface charge density σ1 = -2

pishuonlain [190]

Answer:

$E_{total}=4.82*10^6N/C$

vector with direction equal to the axis X.

Explanation:

We use the Gauss Law and the superposition law in order to solve this problem.

<u>Superposition Law:</u> the Total Electric field is the sum of the electric field of the first infinite sheet and the Electric field of the second infinite sheet:

$E_{total}=E_1+E_2$

<u>Thanks Gauss Law</u> we know that the electric field of a infinite sheet with density of charge σ is:

$E=\sigma/(2\epsilon_o)$

Then:

$E_{total}=(\sigma_1+\sigma_2)/(2\epsilon_o)=(-2.7*10^{-6}+88*10^{-6})/(2*8.85*10^{-12})=4.82*10^6N/C$

This electric field has a direction in the axis perpendicular to the sheets, that means it has the same direction as the axis X.

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3 years ago

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A sports car accelerates from rest for 5 seconds reaching a velocity of 23.0 m/s.

denis-greek [22]

Answer:

<h2>4.6 m/s²</h2>

Explanation:

The acceleration of an object given it's velocity and time taken can be found by using the formula

<h3> $a = \frac{v - u}{t} \\$ </h3>

where

v is the final velocity

u is the initial velocity

t is the time taken

a is the acceleration

Since the body is from rest u = 0

From the question we have

$a = \frac{23 - 0}{5} = \frac{23}{5} \\$

We have the final answer as

<h3>4.6 m/s²</h3>

Hope this helps you

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2 years ago

Helppp!!! what's the answer to this??

riadik2000 [5.3K]

Answer:

(b)

Explanation:

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2 years ago

A student drops two metallic objects into a 120-g steel container holding 150 g of water at 25°C. One object is a 206-g cube of

spayn [35]

Answer:

Mass of the aluminium chunk = 278.51 g

Explanation:

For an isolated system as given the energy lost and gains in the system will be zero therefore sum of all transfer of energy will be zero,as the temperature will also remain same

A specific heat formula is given as

Energy Change = Mass of liquid x Specific Heat Capacity x Change in temperature

Q = m×c×ΔT

Heat gain by aluminium + heat lost by copper = 0 (1)

For Aluminium:

Q = $m\times0.897\frac{J}{g.k}\times(25-5)$

Q = m x 17.94 joule

For Copper:

$Q= 206g\times0.385\frac{J}{g.k} \times(88-25)$

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3 years ago

A circular loop of wire with a diameter of 0.626 m is rotated in a uniform electric field to a position where the electric flux

Mila [183]

Answer:

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Explanation:

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$\Phi = EA cos \theta$

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$\Phi = EA$

Here we have:

$\Phi = 7.50\cdot 10^5 N/m^2 C$ is the flux

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3 years ago