High School

A 100-W driveway light bulb is on for 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 :

The yearly cost to operate the 100-W driveway light bulb, if it is used every day for a 365-day year, is approximately $36.50.

1. Determine the energy consumption per day:

The bulb uses 100 watts of power and is on for 10 hours each day. Therefore, the daily energy consumption is:

[tex]\[ 100 \text{ W} \times 10 \text{ hours} = 1000 \text{ Wh/day} \][/tex]

2. Convert the daily energy consumption to kilowatt-hours:

Since there are 1000 watts in a kilowatt, we convert the daily energy consumption to kilowatt-hours (kWh):

[tex]\[ 1000 \text{ Wh/day} \div 1000 = 1 \text{ kWh/day} \][/tex]

3. Calculate the yearly energy consumption:

The bulb is used every day for a year, so the yearly energy consumption is:

[tex]\[ 1 \text{ kWh/day} \times 365 \text{ days/year} = 365 \text{ kWh/year} \][/tex]

4. Determine the cost per kilowatt-hour:

The power company charges 10¢ per kWh, which is equivalent to $0.10 per kWh.

5. Calculate the yearly cost:

Multiply the yearly energy consumption by the cost per kWh to find the yearly cost:

[tex]\[ 365 \text{ kWh/year} \times \$0.10/\text{kWh} = \$36.50/\text{year} \][/tex]

Therefore, the yearly cost to operate the bulb is approximately $36.50.

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:

[tex]T=t\cdot 365 = 10 \cdot 365 =3650 h[/tex]

So the total energy consumed by the light bulb is

[tex]E=PT=(0.1 kW)(3650 h)=365 kWh[/tex]

We know that the cost of operation is

p = 10 cents/kWh

Therefore, the total cost will be:

[tex]c=E\cdot p =(365)(10)=3650 c[/tex]

So, 3650 cents, or 36.50$.