Question

A new LCD high definition TV has a power consumption of 128 watts when operating at 120 volts. How much energy, in kilojoules, would be used in 2.5 hours?

A. 1152 kilojoules
B. 1200 kilojoules
C. 1552 kilojoules
D. 1725 kilojoules

Answer 1

For this item, we are given with the power consumption in watts and the time that the new LCD high definition TV was used. The energy is calculated by multiplying the power with time. That is,
Energy = Power x time
Energy = (128 J/s) x (2.5 hours) x (3600 s/ 1 hour)
Energy = 1152000 J
Energy = 1152 kJ
Therefore, the answer to this item is letter C.