How Do You Calculate Time in a Charging Capacitor Equation?

[MidlandSoul]

Homework Statement

Solving the equation: V = V0*[1 - e^(-t/RC)]

Homework Equations

Need to solve this equation for time to calculate the time at which a charging capacitor achieves a certain voltage across it's plates.

The Attempt at a Solution

I solve it as: t = -RC*ln(V/V0) but this doesn't seem to work. Help!

 

[BruceW]

it looks like you might have done a step like this: ln(1+x) = ln(x) But this is not true.

Edit: Oh, welcome to physicsforums by the way!

 

[rude man]

Show your work step by step & we'll show you where you went wrong.

 

[haruspex]

it looks like you might have done a step like this: ln(1+x) = ln(x)

Or rather, ln(1-x) = ln(x)

 

[MidlandSoul]

Thanks guys. I think our lecturer intends for us to sort of 'have a guess' by inspection and using time constant ratios than actually solve this, so I can leave it for another day, phew!
Thank you for the feedback nonetheless.