(e) State two ways in which this household can reduce electrical energy consumption.

6. An air conditioner has a power rating of 3000 W and is used daily. Its electrical energy consumption is 120 kWh for one week.

(a) Calculate, in hours, the average duration for which the air conditioner is used daily.

(b) Given that the cost of electricity is $0.25 per kWh, calculate the total cost of using the air conditioner for one week.

(a) To calculate the average duration the air conditioner is used daily, we can use the information given about its energy consumption and power rating. The energy consumption for one week is 120 kWh. To find the daily usage, we will first find the total power consumed in hours per week and then divide it by the number of days in a week.
We know:

Energy consumed per week = 120 kWh
Power rating of the air conditioner = 3000 W = 3 kW

The total hours the air conditioner was used in one week can be found using the formula: Total time (in hours) = Power rating (kW) Energy consumed (kWh) ​ Total time (in hours) = 3 120 ​ = 40 hours
Now, to find the average duration of daily use: Daily usage (in hours) = 7 40 ​ ≈ 5.71 hours per day
(b) To calculate the total cost of using the air conditioner for one week:
The cost per kWh is $0.25, and the total energy consumed in one week is 120 kWh.
Therefore, the total cost is: Total cost = Energy consumed (kWh) × Cost per kWh Total cost = 120 × 0.25 = $30
(e) Two ways in which this household can reduce electrical energy consumption:

Programmable Thermostat : Install a programmable thermostat to adjust the air conditioner's operation according to the household's schedule, reducing unnecessary usage.

Regular Maintenance : Perform regular maintenance on the air conditioner to ensure it operates efficiently, which can reduce energy consumption. Maintenance includes cleaning or replacing filters and checking the system's refrigerant levels.

Answered by AvaCharlotteMiller | 2025-07-06