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galina1969 [7]
3 years ago
9

A lamp is 10% efficient.How much electrical energy must be supplied to the lamp each second if it produces 20 J of light energy

per second?
Physics
1 answer:
k0ka [10]3 years ago
6 0

If it produces 20J of light energy in a second, then that 20J is the 10% of the supply that becomes useful output.

20 J/s = 10% of Supply

20 J/s = (0.1) x (Supply)

Divide each side by 0.1:

Supply = (20 J/s) / (0.1)

<em>Supply = 200 J/s  </em>(200 watts)

========================

Here's something to think about:  What could you do to make the lamp more efficient ?  Answer:  Use it for a heater !

If you use it for a heater, then the HEAT is the 'useful' part, and the light is the part that you really don't care about.  Suddenly ... bada-boom ... the lamp is 90% efficient !

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3 years ago
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expeople1 [14]

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B

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Light from distant galaxies most likely shows a ...red shift, indicating that the universe is expandingblue shift, indicating th
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Answer:

red shift, indicating that the universe is expanding

Explanation:

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5 0
3 years ago
1. An 800-gram bowling ball is rolling in a straight line toward you. If its momentum is 16 kg•m/sec, how fast is it traveling?
ziro4ka [17]

<u>Answer:</u>

The ball is rolling at a speed of 0.02 meter per second.

<u>Step by step explanation:</u>

We are given that there is a 800 gram bowling ball rolling in a straight line. If its momentum is given to be 16 kg.m/sec, we are to find its velocity.

For this, we will use the formula of momentum.

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3 years ago
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Explanation:

5 0
2 years ago
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