Watt conversion question

StudentofPhysics

The electronic flash attachment for a camera contains a capacitor for storing the energy used to produce the flash. In one such unit, the potential difference between the plates of a 765 µF capacitor is 345 V.

(a) Determine the energy that is used to produce the flash in this unit.

Using the formula:
Energy = .5C(V^2) i found the energy to be 45.527 J

(b) Assuming that the flash lasts for 5.0 10-3 s, find the effective power or "wattage" of the flash.


I can not find a formula to convert the given information into wattage however.

fargoth

i'd calculate the energy difference on the capacitor (before and after the flash) and devide it by the time of the flash...

neutrino

The defenition of power is the change in energy per unit time. Can you do the problem now?

StudentofPhysics

how do i know what the energy is before and after the flash? Would it be that energy before then 0 after?

StudentofPhysics

ok, i undersstand know. I take the energy I found and simply divide it by the time passed. Thank you.