How Do I Calculate Theoretical Charge and Discharge Times in RC Circuits?

AI Thread Summary
To calculate theoretical charge and discharge times in RC circuits, the user has derived formulas for both processes: t=ln(1-Vc/V0)x-RC for charging and t=ln(Vc/V0)xRC for discharging. However, there is uncertainty regarding the correctness of these formulas and how to proceed without knowing the capacitor voltage (Vc). The discussion highlights a lack of clarity in the assignment and the need for assistance in understanding the calculations. Additionally, there is a mention of an unreadable document linked in the conversation. Overall, the user seeks guidance on accurately determining charge and discharge times in RC circuits.
d_sx
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I've been set the following assignment on RC circuits that I thought I understood. Turns out I don't:

http://www.geocities.com/danielessex/images/electronicsmain.jpg

I understand what is happening in the circuit and what it is asking me to do but I don't really know how to go about it.

When i transposed the charging formula i got:
t=ln(1-Vc/V0)x-RC

When i transposed the discharging formula i got:
t=ln(Vc/V0)xRC

Not really sure if these are correct but if they are, how do I go about calculating the theoretical charge and discharge times when I don't know Vc

I might just be being stupid but Maths and Physics were never my strong points so any help would be much appreciated (or if you want to do the assignment I wouldn't mind ;P)

Thanks for you time and help,
Dan - Edinburgh, Scotland
 

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Just like to say thanks for the 'overwhelming' response from you all.!

Thanks a bunch!
 
well, I'm not sure about everyone else, but the document in your first link is unreadable on my computer.
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

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Thread 'Struggle to understand the concept of the question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
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