//Horizontal force required at certain height to avoid slipping
//Refer fig. 3.23 
//applying equilibrium conditions we get
//F=RB...(1)
//-RB*3+700*2*cotd(60)+100*1.5*cotd(60)+F=0...(2)
//Solving (1)&(2) we get
F=(700*2+100*1.5)*cotd(60)/2  //N
printf("Required force is F=%.2f N",F)