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2 years ago

15

A lamp is 15% efficient. How much electrical energy must be supplied to the lamp each second if it produces 30 J of light energy

per second? *WILL MARK BRAINLIEST*

2 answers:

dem82 [27]2 years ago

7 0

200 Joules should be supplied in the circuit.

Efficiency = output/inupt

Here the output is 30J and input is missing

$\sf \dfrac{30}{I} * 100 = 15$

multiplied with 100, to covert it into percentage

$\sf 3000 = 15(I)$

$\sf I = \dfrac{3000 }{15}$

$\sf I = 200J$

sammy [17]2 years ago

7 0

Let that be X

Efficiency is 15% means the lamp produces 15J of light energy when 100J energy applied.

$\\ \rm\Rrightarrow \dfrac{30}{x}(100)=15$

$\\ \rm\Rrightarrow 3000=15x$

$\\ \rm\Rrightarrow x=200J$

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Read 2 more answers

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Part b)

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Part c)

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Part d)

from t = 0 to t = 4.9 s

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So it will read same as that of the mass

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Part b)

When elevator is decending with constant speed then we will have

$F_{net} = 0$

$T - mg = 0$

$T = mg$

So it will read same as that of the mass

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Part c)

When elevator is ascending with constant speed 39 m/s and acceleration 10 m/s/s then we will have

$F_{net} = ma$

$T - mg = ma$

$T = mg + ma$

Reading is given as

$Reading = \frac{mg + ma}{g}$

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$Reading = 4.04 kg$

Part d)

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from t = 0 to t = 4.9 s

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The reading of the scale will be less than the actual mass

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