Question

1. calculate how much electrical energy, in kilowatt - hours, does a 200 w light bulb use if it is left on for 12 h? show your work.

Explanation:

Step1: Convert power from watts to kilowatts

Since \(1\space kW = 1000\space W\), then \(P = 200\space W=\frac{200}{1000}\space kW = 0.2\space kW\)

Step2: Use the formula \(E=P\times t\)

Given \(t = 12\space h\) and \(P=0.2\space kW\), then \(E=0.2\space kW\times12\space h\)

Answer:

\(2.4\space kWh\)