Center of mass - Going nuts!

Hello We are given a task, where we have to calculate the center of mass of an area given by 3 functions. We have to do it numerical using symbolic toolbox.

My problem is how to calculate it using a vectors and sum function. I have found the mass and the x-coordinate, but the y-coordinate are giving me trouble. My code is like this:

syms x

f1(x)=3-x;

f2(x)=x-1;

f3(x)=-x^2+4*x-1;

m=1; x1plot = 1:0.001:2; x2plot = 2:0.001:3;

M1=m*(sum(f3(x1plot))-sum(f1(x1plot)))*0.001; M2=m*(sum(f3(x2plot))-sum(f2(x2plot)))*0.001; M=M1+M2;

'The mass' vpa(M)

Xko=sum((1/M)*m*x1plot.*((f3(x1plot)-f3(x2plot))+(f1(x1plot)+f2(x2plot)))*0.001)

'x koor'

vpa(Xko)

Yk2=(f1(x1plot)-f2(x2plot)+(f3(x1plot)+f3(x2plot)))/2

Yko=sum((1/M)*m*((f3(x1plot)-f3(x2plot))+(f1(x1plot)+f2(x2plot))).*Yk2*0.001)

'Y koor' vpa(Yko)

I hope that you are able to see my problem and hopefully give me an answer. Thank you!

[sixwwwwww]

I run you code and didn't get any error. Can you specify what error are you getting?

Answer 1

[Rasmus]

No particullar errors, but i now from mupad, that the value has to be around 2.08 and not 3.3 so i now something isn't correct.

Answer 2

[sixwwwwww]

Dear Rasmus, I run your code and got these two values:

Xko =
   2.000428632661809
Yko =
   3.357265323617660

Are these values not correct?