# Charge passing through a cross section for a time varying current

1. Apr 8, 2017

### superslow991

1. The problem statement, all variables and given/known data
The current in a wire varies with time according to the equation I(t) = 6.00 A + (4.80 A/s)t, where t is in seconds. How many coulombs of charge pass a cross section of the wire in the time period between t = 0.00 s and 3.00 s

2. Relevant equations
I=dq/dt

3. The attempt at a solution
So since were calculating the current, i solved for q=(integral)I*dt which was the integral from 0 to 3 (6.00A+(4.80)t and got the answer q = 75.6 which is wrong. The answer is q= 39.6.
I know the problem lies in the math but im not sure where im wrong.

Last edited by a moderator: Apr 9, 2017
2. Apr 9, 2017

### TomHart

Can you write out your steps in performing your integral so we can see where you made a mistake.

Edit: Maybe you attempted to post a picture and it didn't show up.

3. Apr 9, 2017

### superslow991

Actually i think i input my equation wrong i got the right answer