大学物理上——复习系统c++代码

此为本人在大二上学期准备物理期末考试时于闲暇时间所写代码，可在dev编译器中进行编译使用，聊以慰藉。现附源码如下：

#include 
#include 
using namespace std;
int main()
{
	cout<<"----------------------\n"<<endl;
	cout<<"    大学物理复习系统    \n"<<endl;
	cout<<"    制作人：方寸谛\n"<<endl;
	cout<<"------------------------"<<endl;
	A:
	system("pause");
	system("cls");
	cout<<"请选择模块"<<endl;
	cout<<"------------------------"<<endl;
	cout<<"    1、电场基础"<<endl;
	cout<<"    2、电场场强"<<endl;
	cout<<"    3、电场电势"<<endl;
	cout<<"    4、电场电容"<<endl;
	cout<<"    5、磁场场强"<<endl;
	cout<<"    6、磁场力"<<endl;
	cout<<"    7、磁化"<<endl;
	cout<<"    0、结束"<<endl;
	cout<<"------------------------"<<endl;
	int a;
	cin>>a;
	system("cls"); 
	switch(a) {
		case 0:{
			return 0;
		}
		case 1:{
			cout<<"库仑定律：F=k(q1*q2)/r^2，k=1/4πE0=9.0x10^9"<<"\n"<<endl;
			Sleep(250);
			cout<<"电偶极矩：p=q*l"<<"\n"<<endl;
			Sleep(250);
			cout<<"电力矩：M=pxE，电偶极矩与电场强度的叉乘"<<"\n"<<endl;
			Sleep(250);
//			cout<<"公式："<
//			cout<<"  A∪B=A∩!B∪B"<
//			cout<<"  P(A-B)=P(A∩!B)=P(A)-P(AB)，B∈A时，P(A-B)=P(A)-P(B)"<
//			cout<<"  P(A∪B)=P(A)+P(B)-P(AB)，可推广"<
//			Sleep(250);
			break;
		}
		case 2:{
			cout<<"场强：E=F/q，不能E=|dE，要Ex=|dEx，再叠加"<<"\n"<<endl;
			cout<<"  静止点电荷：E=k*q/r^2"<<"\n"<<endl;
			cout<<"  点电荷系电场：对E求矢量和"<<"\n"<<endl;
			cout<<"  连续带电体：ρ=dq/dv体密度，E=|k*ρdv/r^2，可推导到面、线"<<"\n"<<endl;
			cout<<"  无限长电线：E=ρ/2πE0d，ρ为线密度，d为距离"<<"\n"<<endl;
			cout<<"  无限大平面：E=ρ/2E0，ρ为面密度，是均匀电场"<<"\n"<<endl;
			cout<<"  圆盘：E=k*q/x^2，q为带电量，x为距离"<<"\n"<<endl;
			cout<<"  球面：k*q/r^2，r为到球心的距离，球面内为0"<<"\n"<<endl;
			cout<<"  柱面：ρ/2πE0r，ρ为面密度，r为到面的垂直距离"<<"\n"<<endl;
			Sleep(250);
			cout<<"高斯定理：闭合曲面上对的场强的面积分等于曲面包围的电荷量与E0的比值"<<"\n"<<endl;
			Sleep(250);
			cout<<"极化强度：P=p/v=E0*Xe*E，电偶极矩的矢量和与单位体积的比值，Xe为电极化率"<<"\n"<<endl;
			Sleep(250);
			cout<<"电位移矢量：D=E0*Er*E=E*E，Er为相对介电常数=1+Xe，E为绝对介电常数**"<<"\n"<<endl;
			Sleep(250);
			cout<<"极化电荷面密度：ρ=dq/ds=P·n，极化强度的面方向的分量"<<"\n"<<endl;
			Sleep(250);
			cout<<"极化电荷量：\n  -q'=|Pds，极化电荷量=极化强度的面积分"<<"\n"<<endl;
			cout<<"  q0=|Dds=|(E0*E+P)ds，自由电荷量=电位移矢量的面积分"<<"\n"<<endl;
			cout<<"  E0|Eds=q0+q'，总电荷量=电场强度的面积分*常数"<<"\n"<<endl;
			Sleep(250);
			cout<<"静电场的能量密度：dW=du/dv=E0*Er*E^2/2，W=CU^2/2=QU/2=|||dWdv，对dW的体积分"<<"\n"<<endl;
			break;
		}
		case 3:{
			cout<<"电势：Ua-Ub=Wab/q0=|Edl，a为起点，b为终点"<<"\n"<<endl;
			cout<<"  静止点电荷：q/4πE0r"<<"\n"<<endl;
			cout<<"  点电荷系电场：对U求代数和"<<"\n"<<endl;
			cout<<"  有限长电线：q/(8πE0l)ln((x+l+√((x+l)^2+y^2))/(x-l+√((x-l)^2+y^2)))"<<"\n"<<endl;
			cout<<"  无限长电线：ρ/(2πE0)ln(a/r)"<<"\n"<<endl;
			cout<<"  球面：k*q/r，r为到球心的距离，球面内部为定值k*q/R"<<"\n"<<endl;
			Sleep(250);			
			break;
		}
		case 4:{
			cout<<"电容：C=q/U"<<"\n"<<endl;
			Sleep(250); 
			cout<<"  平行板电容器：C=E0*S/d，d为板间间距"<<"\n"<<endl;
			cout<<"  孤立导体球：C=4πE0*R"<<"\n"<<endl;
			cout<<"  同心球壳：C=(4πE*R1*R2)/(R2-R1)"<<"\n"<<endl;
			cout<<"  同心圆柱：C=2πE*l/(ln(R2/R1))"<<"\n"<<endl;
			Sleep(250);
			cout<<"串联时为倒数的和，耐压值升高；并联时为和，耐压值为最小值"<<"\n"<<endl;
			Sleep(250);
			break;
		}
		case 5:{
			cout<<"磁场强度：dB=μ0*I*dlxr/4πr^3，μ0=4πx10^-7磁导率，dl为对导线的微分，r为距离"<<"\n"<<endl;
			cout<<"  B=|dB，对dB的线积分，μ0/4π|I*dlxr/r^3"<<"\n"<<endl;
			Sleep(250);
			cout<<"  有限长电线：B=|dB=μ0*I(cosθ1-cosθ2)/4πa，a为距离，在线上为0"<<"\n"<<endl;
			cout<<"  无限长导线：B=μ0*I/2πa，θ1=0，θ2=π"<<"\n"<<endl;
			cout<<"  线圈：B=|dB//=μ0*R^2*I/2(R^2+r^2)^(3/2)，中心为μ0*I/2R，无限远为μ0*I*S/2πr^3"<<"\n"<<endl;
			cout<<"  螺线管：B=μ0*n*I(cosθ2-cosθ1)/2，两端为μ0*n*I/2，无限长为μ2*n*I"<<"\n"<<endl;
			Sleep(250);			
			cout<<"磁通量：dφ=Bcosθds=Bds，φ=|Bds，单位面积上磁感线线的条数"<<"\n"<<endl;
			Sleep(250);			
			cout<<"高斯定理：磁场内的闭合曲面磁通量为0"<<"\n"<<endl;
			Sleep(250);			
			cout<<"安倍环路定理：|Bdl=μ0*Ia，闭合曲线上的磁场强度的积分等于曲面穿过的电流的代数和乘μ0，进恒定电流，对称性"<<"\n"<<endl;
			Sleep(250);
			break;
		}
		case 6:{			
			cout<<"安倍力：dF=IdlxB，F=|IxBdl，安倍力等于电流与磁场强度的叉乘的线积分"<<"\n"<<endl;
			Sleep(250);						
			cout<<"磁矩：Pm=I·S，磁力矩：M=PmxB"<<"\n"<<endl;
			Sleep(250);			
			cout<<"功：A=|I(φ2-φ1)"<<"\n"<<endl;
			Sleep(250);			
			cout<<"洛仑磁力：f=q*vxB，右手法则"<<"\n"<<endl;
			Sleep(250);			
			cout<<"霍尔效应：U=Rh*I*B/d=I*B/(n*q*d)，d为沿B方向的厚度"<<"\n"<<endl;
			Sleep(250);
			break;
		}
		case 7:{			
			cout<<"相对磁导率：μr，绝对磁导率μ=μ0*μr"<<"\n"<<endl;
			cout<<"  B=B0+B'=μr*B，顺磁质μ略大于μ0，Pm!=0；抗磁质μ略小于μ0，Pm=0，铁磁质μ远大于μ0"<<"\n"<<endl;
			Sleep(250);			
			cout<<"磁化强度矢量：M=lim(Pm/dv)=(Pm+Pm')/dv=jmxn0，面电流密度矢量与方向矢量的叉乘0"<<"\n"<<endl;
			cout<<"  Im=|Mdl，闭合环路的环流=穿过面的磁化电流的代数和，仅存在于介质表面"<<"\n"<<endl; 
			Sleep(250);			
			cout<<"磁场强度矢量：H=B/μ0-M，与B同向，|Hdl=I0，即对H求环路积分为穿过面的传导电流代数和\nB=B0+B'，最后的场强=原场强+附加场强"<<"\n"<<endl;
			cout<<"  |Bdl=|(B0+B')dl=μ0(I0+Im)，I0为传导电流代数和，Im为磁化电流代数和"<<"\n"<<endl;
			cout<<"  M=Xm*H,Xm为磁化率，μr=1+Xm"<<"\n"<<endl;
			cout<<"  B=μ0(1+Xm)H=μ0μrH=μH"<<"\n"<<endl; 
			Sleep(250);			
			cout<<"铁磁质：Hc矫顽力，Br剩磁"<<"\n"<<endl;
			cout<<"  软磁材料：Hc小，Br小，S小，用于电机，变压器"<<"\n"<<endl;
			cout<<"  硬磁材料：Hc大，Br大，S大，用于永磁体"<<"\n"<<endl;
			cout<<"  矩磁材料：像举行，Br≈Bs，磁极可迅速翻转"<<"\n"<<endl;
			Sleep(250);			
			cout<<"居里点Tc：距离点以上，铁磁质成为顺磁质，降温后恢复"<<"\n"<<endl;
			Sleep(250);
			break;
		}
		default:{
			cout<<"输入错误"<<endl; 
		} 
	} 
	goto A;
	return 0;
 }