Question

A car stereo pulls 2.89 A from a car's battery. If the battery has a voltage of 12 V, how much power does it use?

Answer 1

In order to calculate the power, we can multiply the voltage and the current:

$P=I\cdot U$

So we have:

$\begin{gathered} P=2.89\cdot12\\ \\ P=34.68\text{ W} \end{gathered}$

Therefore the power is 34.68 W.