What is the code that is missing for the calculation? Please fill it in. The calculations are for the whole system not the individual objects. Looking for K, U and W.

from __future__ import division from visual import * from visual.graph import *

# CONSTANTS G = 6.7e-11 mEarth = 6e24 mCraft = 15e3 mMoon = 7e22 delta_t = 10 t_0 = 0 t_f = 60*24*60*60 ## 60 days

# OBJECTS AND INITIAL VALUES display( title='A space-craft voyage from the Earth to the Moon, and back', x = 0, y = 200, width = 1000, height = 500 )

Earth = sphere(pos=vector(0,0,0), radius=6.4e6, color=color.cyan) craft = sphere(pos=vector(-10*Earth.radius, 0,0),radius = 1.5e6, color=color.yellow) Moon = sphere(pos=vector(4e8,0,0), radius=1.75e6, color=color.red)

vCraft = vector(0,3.27e3,0) pCraft = mCraft*vCraft

trail = curve(color=craft.color) ## craft trail: starts with no points

# Create graph axes for plotting the energies of the system

# create the graph axes for plotting the cumulative work

# CALCULATIONS t=t_0 W=0

KUgraph = gdisplay(title = 'K, U, and K + U vs. t', x=0, y=0, width=500, height=200) Kcurve = gcurve( color=color.yellow) Ucurve = gcurve( color=color.red) KUcurve=gcurve(color=color.cyan)

Wgraph = gdisplay(title= 'Comulative Work done on craft', x=500, y=0, width = 500, height = 200) Wcurve = gcurve(color=color.green) while t < t_f: rate(40000)

## update Gravitational Force (Earth and Spacecraft) rEarthCraft = craft.pos - Earth.pos rhatEarthCraft = rEarthCraft / mag( rEarthCraft ) magFEarth = ((G * mCraft * mEarth) / mag2( rEarthCraft )) FEarth = -magFEarth * rhatEarthCraft

## update Gravitational Force (Moon and Spacecraft) rMoonCraft = craft.pos - Moon.pos rhatMoonCraft = rMoonCraft / mag( rMoonCraft ) magFMoon = ((G * mCraft * mMoon) / mag2( rMoonCraft ) ) FMoon = -magFMoon * rhatMoonCraft

Fnet = FEarth + FMoon # check to see if the spacecraft has crashed on the Earth if mag( rEarthCraft ) < Earth.radius: break

if mag( rMoonCraft ) < Moon.radius: break

## momentum pCraft = pCraft + (Fnet*delta_t)

## update Position delta_r = (pCraft/mCraft)*delta_t craft.pos = craft.pos + delta_r

# Calculate energies of the system (consisting of all three objects) K = ## you must complete this line U = ## you must complete this; omit the constant term for the Earth-Moon

# Calculate cumulative work done internally by the system. W = W + # you must complete this line.

# Add the data to the 4 curves in the plots ## this adds the new position of the spacecraft to the trail trail.append(pos=craft.pos) t = t+delta_t print 'Calculations finished after ', t, 'seconds'