Question

how much electrical energy is used by a 75 w laptop that is operating for 12 minutes?
a. 27,000 j
b. 108,000 j
c. 54,000 j
d. 900 j

Explanation:

Step1: Convert time to seconds

The formula for electrical energy \(E = P\times t\) (where \(P\) is power and \(t\) is time). Given \(P = 75\space W\), \(t=12\space min\). Since \(1\space min = 60\space s\), then \(t = 12\times60\space s=720\space s\).

Step2: Calculate electrical energy

Substitute \(P = 75\space W\) and \(t = 720\space s\) into \(E=P\times t\). So \(E=75\times720\space J = 54000\space J\)

Answer:

C. \(54,000\space J\)