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OLga [1]
3 years ago
11

A power station burns 75 kilograms of coal per second. Each kg of coal contains 27 million joules of energy.

Physics
1 answer:
Kaylis [27]3 years ago
3 0

Answer:

Explanation:

a )

one kg of coal gives energy of 27 x 10⁶ J

75 kg of coal gives energy of 27 x 10⁶ x 75 J

So rate which energy is coming out of coal per second

= 27 x 10⁶ x 75 J

= 2025 x 10⁶ J /s

2025 million watts .

b ) energy output = 800 million watts

efficiency = (800 / 2025) x 100

= 39.5 % .

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zvonat [6]

Answer:

0.293I_0

Explanation:

When the unpolarized light passes through the first polarizer, only the component of the light parallel to the axis of the polarizer passes through.

Therefore, after the first polarizer, the intensity of light passing through it is halved, so the intensity after the first polarizer is:

I_1=\frac{I_0}{2}

Then, the light passes through the second polarizer. In this case, the intensity of the light passing through the 2nd polarizer is given by Malus' law:

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Here we have

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5 0
3 years ago
How much momentum does a 10 kg object have when is moving 30 m/s
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3 0
3 years ago
Suppose of methane are burned in air at a pressure of exactly and a temperature of . Calculate the volume of carbon dioxide gas
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4 0
3 years ago
The period (T) of an oscillating wave is 1/5s. What happens to the frequency (f) of the wave if T increases to 1/2s
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Answer:

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