Question

How does the energy used by a 100 W lightbulb compare with the energy used by a 40 W lightbulb in a given amount of time? The 100 W bulb uses 2.5 times more energy. The 40 W bulb uses 2.5 times more energy. The 100 W bulb uses 60 times more energy. The 40 W bulb uses 60 times more energy.

Answer 1

The 100 W bulb uses 2.5 times more energy

Step-by-step explanation:

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Answer 2

The correct answer is
The 100 W bulb uses 2.5 times more energy

In fact, the power is the amount of energy used per unit of time. This means that the light bulb of 100 W uses 100 J in one second, and the light bulb of 40 W uses 40 J in one second, and if we compare the two numbers, we get

`(100 J)/(40 J)=2.5`
so, the 100 W light bulb uses 2.5 times more energy than the 40 W light bulb.