Matlab在物理上的应用举例VIP免费

1. 单列波 %%单列波 t=0:0.001:10; A=input('振幅A='); w=input('频率w='); a=input('a='); y=A.*sin(w.*t+a); plot(t,y); pause(1),sound(y); ylabel('y'),xlabel('t') 2. %%光的单缝衍射现象 Lambda=500e-9; % a=input('a='); % 可取0.2e-3,1e-3,2e-3 三种情况 z=1 % ymax=3*Lambda*z/a; % Ny=51; % ys=linspace(-ymax,ymax,Ny); % NPoints=51; % yPoint=linspace(-a/2,a/2,NPoints); % for j=1:Ny % L=sqrt((ys(j)-yPoint).^2+z^2); % Phi=2*pi.*(L-z)./Lambda; % SumCos=sum(cos(Phi)); % SumSin=sum(sin(Phi)); % B(j)=(SumCos^2+SumSin^2)/NPoints^2; % end clf,plot(ys,B,'*',ys,B);grid; % 3. %% 用毕奥－沙伐尔定律计算电流环产生的磁场 mu0=4*pi*1e-7; I0=5.0; Rh=1; C0=mu0/(4*pi)*I0; NGx=21;NGy=21; x=linspace(-Rh,Rh,NGx); y=linspace(-3,3,20);y=x; Nh=20; theta0=linspace(0,2*pi,Nh+1); theta1=theta0(1:Nh); y1=Rh*cos(theta1); z1=Rh*sin(theta1); theta2=theta0(2:Nh+1); y2=Rh*cos(theta2); z2=Rh*sin(theta2); dlx=0;dly=y2-y1;dlz=z2-z1; xc=0; yc=(y2+y1)/2; zc=(z2+z1)/2; for i=1:NGy for j=1:NGx rx=x(j)-xc; ry=y(i)-yc; rz=0-zc; r3=sqrt(rx.^2+ry.^2+rz.^2).^3; dlXr_x=dly.*rz-dlz.*ry; dlXr_y=dly.*rx-dlx.*rz; Bx(i,j)=sum(C0*dlXr_x./r3); By(i,j)=sum(C0*dlXr_y./r3); end end clf; quiver(x,y,Bx,By); 4. %%多普勒效应 x0=500;v=50;y0=20; c=330;w=1000; t=0:0.001:30; r=sqrt((x0-v*t).^2+y0.^2); t1=t-r/c; u=sin(w*t)+sin(1.1*w*t); u1=sin(w*t1)+sin(1.1*w*t1); sound(u);pause(5);sound(u1); 5.亥姆霍兹线圈 clear all mu0=4*pi*1e-7; I0=5.0;Rh=1; C0=mu0/(4*pi)*I0; NGx=21;NGy=21; x=linspace(-Rh,Rh,NGx); y=linspace(-Rh,Rh,NGy); Nh=20; theta0=linspace(0,2*pi,Nh+1); theta1=theta0(1:Nh); y1=Rh*cos(theta1); z1=Rh*sin(theta1); theta2=theta0(2:Nh+1); y2=Rh*cos(theta2); z2=Rh*sin(theta2); dlx=0;dly=y2-y1;dlz=z2-z1; xc=0; yc=(y2+y1)/2; zc=(z2+z1)/2; for i=1:NGy for j=1:NGx rx=x(j)-xc; ry=y(i)-yc; rz=0-zc; r3=sqrt(rx.^2+ry.^2+rz.^2).^3; dlXr_x=dly.*rz-dlz.*ry; dlXr_y=dly.*rx-dlx.*rz; Bx(i,j)=sum(C0*dlXr_x./r3); By(i,j)=sum(C0*dlX...