One handy formula for electrical power ... the one that's
most helpful here ... is:
Power = (voltage) x (current).
so Power = (120 volts) x (0.5 ampere) = 60 watts.
Now 60 watts means 60 joules of energy per second.
In one minute, the lamp dissipates
(60 joules/second) x (60 seconds/minute) = 3600 joules/minute.
