Question

Cycling uses metabolic energy at a certain rate. About how many 60-w light bulbs would use the same power as a 68-kg cyclist riding at 15 km/h?

Answer 1

Explanation:

It is given that,

Power of the light bulb, P = 60 W

Mass of the cyclist, m = 68 kg

Speed of the cyclist, v = 15 km/h = 4.166 m/s

Let n is the number of light bulbs that can produced the power of 60 W. So,

$60n=F\times v$

$60n=mg\times v$          

$n=\dfrac{mgv}{60}$

$n=\dfrac{68\times 9.8\times 4.166}{60}$          

n = 46.27

or

n = 46 bulbs

So, 46 bulbs use the same power as 68 kg cyclist uses.