PLOTTING it h h
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Stephen23
on 26 Jul 2020
Original question by Mark Edison Arzobal retrieved from Google Cache (complete with SHOUTING):
"PLOTTING NEWTON'S LAW OF COOLING"
HOW CAN I PLOT THESE CODES IN MATLAB?

Walter Roberson
on 26 Jul 2020
Mark Edison Arzobal : If you feel that the question is unclear, then as you are the person who posted the question, you should be the one that clarifies it.
Answers (1)
Alan Stevens
on 25 Jul 2020
I guess you want to plot Temperature as a function of time. Something like this perhaps:
% Data
T1 = 79.5; % temperature at time t = t1 hours;
T2 = 78; % temperature at time t = t1 + 1 hours
T0 = 98.6; % temperature at time t = 0 hours
TS = 69; % room temperature
% Newton's law of cooling function
T = @(t,k) TS + (T0 - TS)*exp(-k*t);
% Obtain k and t1
kt1 = log( (T0 - TS)/(T1 - TS) );
kt2 = log( (T0 - TS)/(T2 - TS) );
t1 = 1/(kt2/kt1 - 1);
k = kt1/t1;
% Plot temperature decay curve
t = 0:0.1:10; % times in hours
Temps = T(t,k);
plot(t, Temps), grid
xlabel('time [hrs]'), ylabel('temperatures [F]')
2 Comments
Alan Stevens
on 25 Jul 2020
This means let t take the values 0, then 0.1, then 0.2, then 0.3, ... etc all the way up to 10. It sets up an array with t taking on values from 0 to 10 in steps of size 0.1. These values are then passed to the function T, which calculates values of temperature at each of those values of t.
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