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-   -   [matlab] I just want to plot a function that describes position as a function of time (http://www.physicsforums.com/showthread.php?t=434268)

 Raziel2701 Oct2-10 07:36 PM

[matlab] I just want to plot a function that describes position as a function of time

It's an object that's falling from rest. The equation takes into account linear friction. in any case, this is is my code or program of whatever it is called:

m=80;%Mass of ignorance
g=9.8;%Gravity
beta=1.6*10^-4;%Given coefficient for air at STP
D=.4;%Diameter of Palin, assuming she's a spherical object
b=beta*D;%Coefficient of linear friction
t=0:.2:60;

x=(m./b)*(g*t + e^(-b*t./m));

plot(t,x)
grid on
xlabel('time','FontSize',16)
ylabel('Position of Sarah Below Helicopter','FontSize',16)

I get this error:
Error in ==> HW13myprogram at 10
x=(m./b)*(g*t + e^(-b*t./m));

What am I doing wrong?

 Dr Transport Oct3-10 12:24 PM

Re: [matlab] I just want to plot a function that describes position as a function of

replace your equation with

x=(m/b)*(g*t + e.^(-b*t/m));

 hasidim Oct3-10 01:27 PM

Re: [matlab] I just want to plot a function that describes position as a function of

It worked fine for me with:

x=(m./b)*(g*t + exp(-b*t./m));

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