Answer
28800 C or 28.8 kC
Work Step by Step
The first step involves finding the current I using the equation,
P=$V\times I$
Since P=18 W and V= 9 V, I is found to be 2 A
Next, we find the charge through the device using the formula,
Q=$I\times t$
where I= 2 A and t = 4 hours or 14400 seconds
Substituting these values, Q is found to be 28800 C or 28.8 kC
