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Kazeer [188]
3 years ago
8

The efficiency of a device such as a lamp can be calculated using this equation:

Physics
2 answers:
loris [4]3 years ago
6 0

efficiency = (useful energy transferred ÷ energy supplied) × 100

It's easy to use this formula, but we have to know both the useful energy and the energy supplied.  The drawing doesn't tell us the useful energy, so we have to find a clever way to figure it out.  I see two ways to do it:

<u>Way #1:</u>

We all know about the law of conservation of energy.  So we know that the total energy coming out must be  250J, because that's how much energy is going in.  The wasted energy is 75J, so the rest of the 250J must be the useful energy . . . (250J - 75J) = 175J useful energy.

(useful energy) / (energy supplied) =  (175J) / (250J) = <em>70% efficiency</em>

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

<u>Way #2: </u>

How much of the energy is wasted ? . . . 75J wasted

What percentage of the Input is that 75J ? . . . 75/250 = 30% wasted

30% of the input energy is wasted.  That leaves the other <em>70%</em> to be useful energy.

jek_recluse [69]3 years ago
3 0

Answer:

70%

Explanation:

I did the USA Test Prep.

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If a student took seven science classes, his/her at score would be 1200.

<h3>What is a graph?</h3>

A graph is a relationship in which data is presented on the axes of cartesian coordinates. The presentation of the graph must be such that it is easy to read off the graph.

Now we can see that the graph is a plot of SAT scores versus the number of science classes that students take. In this case, the slope would tell us the score per subject of a student in the SAT.

a) The mathematical model that re[resents this graph is;

y =100x + 500

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m = y2 - y1/x2 - x1

m = 600 - 500/1 - 0

m = 100

c) Using the relation;

y = mx + c

m = 100

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y = 100(7) + 500

y = 1200

Thus if a student took seven science classes, his/her at score would be 1200.

Learn more about graph:brainly.com/question/16608196

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10 months ago
17. (16 pts) You set up a two-slit experiment with a laser that produces light with a
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when the two waves interfere with eachother to make a dark spot the periodic difference of the two waves is π . the wave length for 2π is 600nm

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3 years ago
What is density?
a_sh-v [17]

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B- The amount of matter in a certain

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Find the relation, time velocity graph : acceleration of an object, time position graph : ?
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