Final answer:
To find the annual operating cost of a 3.00-W electric clock, convert its power to kilowatts and calculate the total energy used in kWh for the year. Then, multiply the energy by the cost per kWh. The correct cost is approximately $2.36 per year, but this answer is not represented in the provided options.
Step-by-step explanation:
To calculate the cost of operating a 3.00-W electric clock for a year, we first need to convert the power from watts to kilowatts:
Next, we calculate the energy used by the clock in kilowatt-hours (kWh) for a year:
- Energy (kWh/year) = Power (kW) × Time (hours)
- Time is 1 year = 365 days × 24 hours/day = 8760 hours/year
- Energy = 0.003 kW × 8760 hours/year = 26.28 kWh/year
Finally, we calculate the total cost:
- Cost = Energy (kWh) × Cost per kWh
- Cost = 26.28 kWh/year × $0.0900 per kWh = $2.3652/year
The answer is closest to option B, which is $0.657, but it appears there might be an error in the options provided. None of these match the calculated cost. The correct cost to operate the clock is therefore approximately $2.36 per year, which is not listed in the options.