THE WATTAGE OF AN APPLIANCE INDICATES THE AVERAGE POWER CONSUMPTION IN WATTS(W),WHERE 1W =1J/S WHAT IS THE DIFFERENCE IN THE NUMBER OF KJ OF ENERGY CONSUMED PER MONTH BETWEEN A REFFIGERATION UNIT THAT CONSUMES 625 W AND ONE THAT CONSUMES 855W? IF ELECTRICITY COSTS $0.15 OER KWH WHAT IS THE MONTHLY COST DIFFERENCE TO OPERATE THE TWO REFRIGERATORS? (ASSUME 30.0 DAYS IN ONE MONTH AND 24.0 HOURS PER DAY.
To calculate the difference in the number of kilojoules (kJ) of energy consumed per month between the two refrigerators, we need to find the energy consumed by each refrigerator and then subtract one from the other.
Step 1: Calculate the energy consumption of the first refrigerator:
Energy consumed per hour = Power (W) x Time (hours)
Energy consumed per day = Energy consumed per hour x Hours per day
Energy consumed per month = Energy consumed per day x Days per month
For the first refrigerator:
Power (W) = 625 W
Time (hours) = 24 hours
Days per month = 30 days
Energy consumed per hour = 625 W x 1 hour = 625 J
Energy consumed per day = 625 J/hour x 24 hours = 15,000 J
Energy consumed per month = 15,000 J/day x 30 days = 450,000 J = 450 kJ
Step 2: Calculate the energy consumption of the second refrigerator:
Using the same steps as above, for the second refrigerator:
Power (W) = 855 W
Energy consumed per hour = 855 W x 1 hour = 855 J
Energy consumed per day = 855 J/hour x 24 hours = 20,520 J
Energy consumed per month = 20,520 J/day x 30 days = 615,600 J = 615.6 kJ
Step 3: Calculate the difference in energy consumption:
Energy consumption difference = Energy consumed by second refrigerator - Energy consumed by first refrigerator
Energy consumption difference = 615.6 kJ - 450 kJ = 165.6 kJ
Therefore, the difference in the number of kJ of energy consumed per month between the two refrigerators is 165.6 kJ.
Now, let's calculate the monthly cost difference to operate the two refrigerators:
Step 4: Calculate the total energy consumed per month in kilowatt-hours (kWh):
1 kilowatt-hour (kWh) = 1000 J / (1000 J/s x 3600 s) = 0.0002778 kWh
Energy consumed per month for the first refrigerator = 450 kJ x 0.0002778 kWh/kJ = 0.125 kWh
Energy consumed per month for the second refrigerator = 615.6 kJ x 0.0002778 kWh/kJ = 0.171 kWh
Step 5: Calculate the monthly cost using the given electricity cost per kilowatt-hour:
Electricity cost per month for the first refrigerator = Energy consumed per month x Cost per kWh
Electricity cost per month for the first refrigerator = 0.125 kWh x $0.15/kWh = $0.01875
Electricity cost per month for the second refrigerator = Energy consumed per month x Cost per kWh
Electricity cost per month for the second refrigerator = 0.171 kWh x $0.15/kWh = $0.02565
Step 6: Calculate the monthly cost difference:
Monthly cost difference = Electricity cost per month for second refrigerator - Electricity cost per month for first refrigerator
Monthly cost difference = $0.02565 - $0.01875 = $0.0069
Therefore, the monthly cost difference to operate the two refrigerators is $0.0069.