Parasitic capacitance influence on lead voltage

[Marcis Rancans]

V' changes over time. How can I determine the influence from parasitic capacitance (~50 pF) on V?
R wire ~ 100 ohm. If I need to read data (V' can change rapidly) from this at 50hz, does it influence reading accuracy? How can I determine values from which I need to be careful when reading data (when τ=RC>0,02sec ?)

https://lh5.googleusercontent.com/YxtTJvFj8vYphq43bW3FTw0ygk7D0WOJPVmzetsrsRsbclgyXy9ErGz6jA=s300

 

[rumborak]

This will all depend on how V' is changing over time. Is it a sine wave? Then the solution will be relatively straightforward to calculate. If V' changes arbitrarily, it won't be nearly as easy :)

 

[Marcis Rancans]

This will all depend on how V' is changing over time. Is it a sine wave? Then the solution will be relatively straightforward to calculate. If V' changes arbitrarily, it won't be nearly as easy :)

V' changes chaotically.

 

[rumborak]

The problem is, all the easy tools that exist for analyzing circuitry presume a steady state, or at least a "periodic steady state".
What you have there is a type of RC circuit, and the only way to deduce the output from an arbitrary input is by solving the differential equation of that system.
For more:

http://en.m.wikipedia.org/wiki/RC_circuit