## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

(a) $E = 7.2\times 10^5~J$ (b) $E = 8.64\times 10^5~J$
(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. $E = P~t$ $E = (10~W)(24~hr)(3600~s/hr)$ $E = (10~J/s)(24~hr)(3600~s/hr)$ $E = 8.64\times 10^5~J$