- #1

Rusty789

- 6

- 0

## Homework Statement

i = 12.5(1-e

^{-t/CR})

Current = i

Resistance = R

Capacitance = C

Time = t

Firstly i had to calculate the current flowing after 0.5s, given a 30k[tex]\Omega[/tex] resistance and a 20µF capacitance.. easily done.

Then i had to work out how long it took to reach 10A, so rearranging the formula with natural logs right? So rearranging to work out t.

**2. The attempt at a solution**

I've done it three times now (different each time just incase i made a stupid error) but forgot to bring my paper work with me but both times I've ended up with a

**-t**and when i put in the numbers it doesnt equal what i'm expecting or the calculator comes up with a math error, from trial and error i'm expecting 966ms or 0.966s. I've done the previous question in which just had letters, so i tried transposing the groups of numbers for letters then working it out after aswell but that didnt work either!