Finding voltage across a parallel plate capacitor with 4 μC charge

[ZeroCool024]

Homework Statement

The plates of a capacitor have an area of 0.4m2 and are separated by a distance of 0.5 micrometers. The material between the two plates is air with a dielectric constant of 1.0 One plate of the capacitor is given the charge of 4$$\muC$$. The voltage across the capacitor is, in volts:

Homework Equations

C=$$\epsilon$$(A/d) C=q/$$\Delta$$V

The Attempt at a Solution

So far I've been trying to calculate the capacitance with the first equation and then use the second equation for finding the change in voltage. I keep coming up with the wrong answer, though. Help please!

 

[rl.bhat]

Show your calculations.

 

[ZeroCool024]

(.4m2/.5$$\mu$$m)x8.85E-12=C

C=q/$$\Delta$$V
$$\Delta$$V=q/C=4$$\mu$$C/Capacitance

 

[ZeroCool024]

I just looked at my calculations and cnai just say sorry if they are a little garbled. I'm having trouble getting used to the way you do calculations on the website. Let me know if you would like me to do them again. Thanks!