# Need help to solve of Matlab code

• MATLAB
When a resistor (R), capacitor (C) and battery (V) are connected in series,
a charge Q builds up on the capacitor according to the formula
Q(t) = CV(1 − e−t/RC)
if there is no charge on the capacitor at time t =0. The problem is to monitor the
charge on the capacitor every 0.1 seconds in order to detect when it reaches a
level of 8 units of charge, given that V =9, R=4 and C =1. Write a program which
displays the time and charge every 0.1 seconds until the charge first exceeds
8 units (i.e. the last charge displayed must exceed 8). Once you have done this,
rewrite the program to display the charge only while it is strictly less than 8 units.

Dear all any one can help me to solve the above quesion on Matlab coz i have exam on it tommorrow

waiting for support ASAP

## Answers and Replies

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Pythagorean
Gold Member
you must first construct a time vector of the numerical values

1. t = ti:dt:tf

where ti is initial time, dt is the change in time (it can't be infinitesimally small on a computer like it can in analytical mathematics, and the closer you go to 0 the more computationally expensive it is).

2. user your equation. don't forget to put a '.' in front of operators on a vector.

other than that, you have to get creative with your code and indexing (possibly with a for loop and/or some if statements) , but that's all I should probably give you. Good luck.