Energy Consumption Calculation

This problem requires calculating the total electrical energy consumed by a lamp over a specific period.

Given:

• Power of the lamp ($P$): 60 W
• Usage time per day ($t_{daily}$): 5 hours
• Duration ($D$): 30 days

Step 1: Convert Power to Kilowatts (kW)

Energy is typically measured in kilowatt-hours (kWh), often called 'units'. First, convert the power from Watts (W) to Kilowatts (kW).

$ P_{\text{kW}} = \frac{P_{\text{W}}}{1000} $

$ P_{\text{kW}} = \frac{60 \text{ W}}{1000} = 0.06 \text{ kW} $

Daily Energy Usage

Step 2: Calculate Daily Energy Consumption

The energy consumed daily is the product of the power in kW and the daily usage time in hours.

$ \text{Energy}_{\text{daily}} = P_{\text{kW}} \times t_{daily} $

$ \text{Energy}_{\text{daily}} = 0.06 \text{ kW} \times 5 \text{ hours} = 0.3 \text{ kWh} $

So, the lamp consumes 0.3 units per day.

Total Energy Consumption Over 30 Days

Step 3: Calculate Total Energy Consumption for 30 Days

Multiply the daily energy consumption by the total number of days.

$ \text{Total Energy} = \text{Energy}_{\text{daily}} \times D $

$ \text{Total Energy} = 0.3 \text{ kWh/day} \times 30 \text{ days} = 9 \text{ kWh} $

The total energy consumed is 9 units (kWh).