grid 70,40
mod m
gen 0,0 0,40 70,40 70,0
gen line 0,0 70,0
gen line 0,40 70,40
gen line 38,0 61,40
gen line 35,33 65,8
prop d=800 bu=2.42 sh=1.46 c=1.67 fri=30 ten=5.8
prop d=2689 bu=36.8 sh=22.3 c=19.8 fri=30 ten=61
prop d=2660 bu=19.8 sh=12 c=4.7 fri=30 ten=13.2
fix x i=1
fix x i=71
fix y j=1
apply yf= i=1,71 j=41
set grav 9.81
step 1000

