bomb.py

from visual import *
from math import *

g=9.80

size=0.3
mass=1000
distance=6000
startvel=0
drag=0.5
rho=1.29
area=3.14159*size*size

bomb=sphere(pos=vector(-distance/2, distance,0), radius=300*size,color=color.green)
bomb.m=mass
bomb.p=vector(0,0,0)

bomb2=sphere(pos=vector(-(distance/2+100*size), distance,0), radius=300*size,color=color.magenta)
bomb2.m=mass
bomb2.p=vector(0,0,0)

observer=sphere(pos=vector(+distance/2,0,0), radius=20, color=color.cyan)
target=sphere(pos=vector(-distance/2,0,0), radius=20, color=color.red)

Fgrav=bomb.m*g*vector(0,-1,0)

t=0
tmax=sqrt(2*distance/g)+12
dt=1

print bomb.p


while bomb.pos.y>0:
    rate(10)
    
    if bomb.p.mag>0:
        vhat=bomb.p/bomb.p.mag
    else:
        vhat=vector(0,-1,0)
        
    Fdrag=-0.5*drag*area*rho*bomb.p.mag2*vhat/(bomb.m*bomb.m)
    Fnet=Fgrav+Fdrag

    bomb.p=bomb.p+Fnet*dt
    bomb.pos=bomb.pos+dt*bomb.p/bomb.m
    r_tar=bomb.pos-target.pos
    rel_v_target=dot(bomb.p,r_tar)/r_tar.mag/bomb.m
    r_obs=bomb.pos-observer.pos
    rel_v_obs=dot(bomb.p,r_obs)/r_obs.mag/bomb.m

    doppler_tar=-rel_v_target/330
    doppler_obs=-rel_v_obs/330
    

    bomb2.p=bomb2.p+Fgrav*dt
    bomb2.pos=bomb2.pos+dt*bomb2.p/bomb2.m
    
    print t,round(bomb.pos.y,0),round(bomb.p.mag/bomb.m,1),round(doppler_tar,3),round(doppler_obs,3)

    t=t+dt