- #1

Mr_Mole

- 6

- 3

- Homework Statement
- I have a homework where I need to use logarithms to make an unknown the subject of a given formula. I know the answer I need (different values in the formula till one worked) but I can’t show how it’s done using logs.

If the flow of current (i), Amperes, in a capacitor at time (t), seconds, increases at an exponential according to the equation below:

i=6.7(1-e^(-t⁄RC) )

The resistance of the circuit is 28kΩ and the capacitance is 15µF.

Calculate the current after 750ms

Calculate the time for the current to reach 5A.

- Relevant Equations
- i=6.7(1-e^(-t⁄RC) )

My attempt that doesn’t work. t=-RC ln(1-I/6.7)