Question

Using matlab, create a 3-D plot of the wave equation y(x,t)= cos(omega*t-beta*x) .Plot for a time range from t=0 to t=2T and a space range of x=0 to x=2lambda

Answer 1

f=100;
w=2*pi*f;
a=1;
x=linspace(-5,5,50);
t=linspace(0,2,50);


for k = 0.05:0.01:2         % Change values of e.g. k
    n = a.*cos(k.*x-w.*t);  % Re-calculate n
    pause(0.02)             % pause to control animation speed
    s = surf(x,t,repmat(n,[length(t),1])); % Use repmat to make Z 2D
    title(['k = ',num2str(k)])

    % Just some nice settings for surf plot
    shading interp
    lighting phong
    camlight left; camlight right; camlight left; camlight right;
    colormap copper
    alpha(.8)
end

In the above code you can easily change the values of x and t according to the values set by you for OMEGA and lambda and the curve will be plot accordingly.

Alternatively, I have a simpler code:'

k=0.05;
f=100;
w=2*pi*f;
a=1;
[x,t]=meshgrid(-5:1:5,0:2:20);
n=a.*cos(k.*x-w.*t);
surf(x,t,n);

Here's the plot which comes up :-