Homework Help: Physical Science

Posted by Stephanie on Wednesday, March 10, 2010 at 6:30pm.

A 9-Volt battery is used to charge a 280 mF capacitor over a 81 Ohms resistance.

How long will it take for the capacitor to reach 75% of its maximum charge?

What formula is relevant?

Physical Science - sam, Wednesday, March 10, 2010 at 10:26pm
charging the capacitor formula;
Q=Q max (1-e ^-t/RC)

Q=qmax= 0.75
solve for t
Physical Science - anony mouse, Thursday, March 11, 2010 at 3:42pm
So the Voltage is irrelevant?
Physical Science - Sandra, Thursday, March 11, 2010 at 10:25pm
Why wouldn't you use this formula?

Q=Qmax*e^(-t/RC)

Answer this Question

Related Questions

physics - 9-Volt battery is used to charge a 375 mF capacitor over a 147 &...
science - Calculate the resistance in a circuit in which a 9-volt battery ...
physical science - how much current flows through a circuit if the resistance is...
physics - A 0.25 mF capacitor is connected to a 9.0 V battery. What is the ...
SCience - An RC-circuit has a time constant of 6x10-3 seconds. The capacitor ...
Science - A 6.0 volt battery is hooked up to a light bulb, whose resistance is 3...
Physics - An RC-circuit has a time constant of 6x10-3 seconds. The capacitor ...
math - A car has a 12 volt battery. The engine has a resistance of 0.22 ohms. ...
physical science - how much current flows through a circuit if the resistence is...
Science - 1. What is the direction of charge flow when charging a capacitor? ...

For Further Reading

First Name:
School Subject:
Answer: