- Energy used by the battery, $E = 810 \ J$
- Time for which the battery runs the radio, $t = 30 \ minutes = 1800 \ s$
To find:
- Power of the radio, $P$
Solution:
The power of the radio is given by the formula:
$$P = \frac{E}{t}$$
Substituting the given values in the formula, we get:
$$P = \frac{810 J}{1800 s} = 0.45 W$$
Therefore, the power of the radio is 0.45 W.