Answer to Question #173025 in Physics for Louis

Question

  How much is the power rating of a light bulb that uses 1.30x 107 J in 1 day?

a. 150 kW b. 150 hp c. 0.15 hp d. 0.15 k

Answer 1

By definition, the power is:

$$P = \dfrac{A}{t}$$

where $A = 1.3\times 10^{7}J$ and $t = 1day = 24\cdot 60\cdot60s = 86400s$ is the time (number of seconds in one day).

Thus, obtain:

$$P = \dfrac{1.3\times 10^{7}J}{86400s} \approx 150W = 0.15\space kW$$

Answer. $0.15\space kW$.