Problema !!!

Quien pueda ayudarme con este problema se irá al cielo jaja:

During an action potential, ions move into the cell at a rate of about 3x10^-7 mol/m^2*s

How much power must be produced by the \"active pumping\" system to produce this flow against a + 25 potential difference? Assume that the axon is 10cm long and 20cm in diameter.

De antemano, muchas gracias =)