Question

A man rides a bicycle that is connected to an electrical generator. If he rides as hard as he can, his body can produce a mechanical power of 500 W, but the generator is only 40% efficient at converting mechanical energy into electrical energy.How many 100 W incandescent light bulbs can he power

Answer 1

Answer: the man can power 2 incandescent light bulbs

Step-by-step explanation:

Given that;

power produced by the body while riding = 500 W

Efficiency of generator = 40% = 0.4

First we need to convert the mechanical energy to electric energy;

which efficiency of generator multiply by power input, so

⇒ 0.4 × 500 = 200 W

Now, if 1 incandescent light bulbs is 100 W

x incandescent light bulbs bulbs is 200 W

100x W= 200 W

x = 200 W / 100 W

x = 2

Therefore, the man can power 2 incandescent light bulbs