Answer:
a) 1512000 Joules
b) 5040 seconds = 84 minutes = 1.4 hours
Explanation:
a) Power saved by replacing bulbs = 60-18 = 42 W = 42 J/s
Time the bulb is used for = 10 hours
Energy saved during this time
42×10×60×60 = 1512000 Joules
Saved energy by replacing standard incandescent lightbulbs with energy-efficient compact fluorescent lightbulbs in 10 hours is 1512000 Joules
b) Power the plasma TV uses = 300 W = J/s
[tex]\frac{1512000}{300}=5040\ s[/tex]
Time a plasma TV can be used for with the saved energy is 5040 seconds = 84 minutes = 1.4 hours.