Question

A 100-W driveway light bulb is on 10 hours per day. If the power company charges 10¢ for each kilowatt-hour of electricity used, estimate the yearly cost to operate the bulb if it is used every day for a 365-day year.

Answer 1

Answer:

36.50$

Step-by-step explanation:

The power of the light bulb in this problem is

P = 100 W = 0.1 kW

And the light bulb is operated for a time of

t = 10 hours

per day.

The light bulb is operated over 1 year (365 days), so the number of hours of operation is:

$T=t\cdot 365 = 10 \cdot 365 =3650 h$

So the total energy consumed by the light bulb is

$E=PT=(0.1 kW)(3650 h)=365 kWh$

We know that the cost of operation is

p = 10 cents/kWh

Therefore, the total cost will be:

$c=E\cdot p =(365)(10)=3650 c$

So, 3650 cents, or 36.50$.