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## Homework Statement

a current of 5 ampere exists in a 10 ohm resistor for 4 minutes

a) how many coulombs pass through the resistor in this time? should be 1200 coulombs

b) how many electrons pass through the resistor in this time? should be 7.5*10^21

c) what potential drop exists across the resistor? should be 50 volts

d) how much energy is dissipated in the resistor during this time? should be 60000joules

## Homework Equations

resistance R = V/I where V is electric potential, I is current

capacitance C = Q/V where Q is charge ---> not sure about this one

current I = nAqv_d where n is number of electrons, A is area, q is charge, v_d is drift velocity

power P = IV where I is current, V is electric potential.

work W = 1/2(CV^2) where C is capacitance

## The Attempt at a Solution

somewhat started part a:

use first eq to solve for electric potential V --> V = IR = 5(10) = 50 volts

tried using second eq, C = Q/V but did not have capacitance, i don't even think you can use capacitance in this problem

i need help with an equation containing time, because t = 4mins = 240seconds. other wise i could use the fourth eq, and let P = W/t where W is work, t is time and solve for t. the work work formula requires capacitance, which i don't have

as for part b and finding the number of elections i think i use the third eq, hold A as constant but how do i figure out the drift velocity v_d, or do i hold that constant too?

i haven't tried the other parts yet, looking for some insight...