Current/Capacitor/voltage problem. .

[violin_writer]

Homework Statement

So this is a problem my calculus professor made me do. I keep getting it wrong and I don't know why.

Prob. #5 For an electronic circuit having a battery of 50 Volts, a resistor of 500 Ohms and a capacitor of .015 Farads, find the current in Amps at t=7.5 seconds if a switch is closed at t=0.

Homework Equations

It uses the following equation "E=E_r+E_c... Where
E = 50 volts.
E_r= 500 ohms*(dq/dt)
E_c= Q/(.015 farads)

The Attempt at a Solution

The beginning and answer is in the first picture, I apologize if it's a little fuzzy or confusing. Basically I need you to tell what I'm doing wrong, point me in a better direction, or check and see if I'm even using the right equation. If you need me to explain my problem more please message me... ty. I'm freaking out over this one.

 

[Nino MMP]

I'm about to get an F on this part of the test and I'm trying to avoid it. ![alt text][1][1]: