//find
clc
//solution
//given
D=400//mm
L=600//mm
r=300//mm
pm=0.3//N/mm^2
p=2.5//N/mm^2
W=50//kN
//T1+T2=6.5//kN=P
P=6.5
q=(%pi/180)*pb
//l/r=5
Fp=(%pi/4)*D^2*p//N
b=2*D
b1=b/2
b2=b/2
H1=Fp*b1/b/1000//kN
H2=Fp*b2/b/1000//kN
//V2=W*c1/c
//c1=c2=c/2
V2=W/2
V2=W/2
H2b=P/2
H3b=P/2
//let dc be crankpin dia,lc be length 
fb=75//N/mm^2
//Mc=(%pi/32)*dc^3*fb=7.364*10^-3*dc^3
Mc1=H1*b2
dc=(Mc1/(7.364*10^-3))^(1/3)
printf("dia of crankpin is,%f mm\n",dc)