Charging/Discharging Capacitor & Magnetic Field

[longcatislong]

Homework Statement

The magnetic field in the region shown below is increasing by 5 T/s. The circuit shown (with R=25 , C=95 µF, dimensions 1 m by 2 m) is inserted into the region as shown. The capacitor is initially uncharged.

See Diagram: http://www.webassign.net/userimages/23-31.gif?db=v4net&id=50305

a.) What is the current in the circuit at the moment the circuit is put in the B field?
.4 A
direction: counterclockwise

b) How long will it take the capacitor to charge to 25% of its final charge?
?

c) How much charge will the capacitor hold after a long time (assuming this magnetic field rate increase is maintained)?
?

Homework Equations

Q(t)=Qf(1-e^t/rc)

Q=VC

The Attempt at a Solution

I'm using Q(t)=Qf(1-e^t/rc) to find time.

First, I found Qf by using Q=VC. I know that V=IR so, Q=IRC, =(.4)(25)(9.5e-6)
Qf=9.5e-5


Then, I used Q(t)=Qf(1-e^t/rc)

.25=9.5e-5(1-e^-t/[(9.5e-5*25)]

I'm not getting a real or correct answer for this.


Your assistance, any help you could offer is much appreciated. THANK YOU!

 

[Emilyjoint]

I think you numbers are correct but when the charge is 25% that means 25% x final charge.
I think you have just forgotten to multiply by the final charge??