Answer
(a) $E = 7.2\times 10^5~J$
(b) $E = 8.64\times 10^5~J$
Work Step by Step
(a) We can find the energy consumed by the hair dryer.
$E = P~t$
$E = (1200~W)(600~s)$
$E = (1200~J/s)(600~s)$
$E = 7.2\times 10^5~J$
(b) We can find the energy consumed by the night light.
$E = P~t$
$E = (10~W)(24~hr)(3600~s/hr)$
$E = (10~J/s)(24~hr)(3600~s/hr)$
$E = 8.64\times 10^5~J$
