HTML_EDITOR author true true This java applet - "RSatellite" was created by J. Hasbun by modifying the original version of ProjectileNSatellite version of Fu-Kwun Hwang with Easy Java Simulation (Ejs) from Francisco
The program's purpose id to simulate a satellite as launcjed from earth. The equations of motion are determined accordin to: Fnet = -GME m/r2+R(v) + u*dm/dt, where the first term is du to the gravitational attraction due to Earth, the second term is the resistive force associated with air resistance from Earth's atmosphere, and the last term is the thrust from the rocket's burning gas. Here, we obtain R from R(v)=-0.5cPAv2, where P is the air density as a function of height z given as P(z)=Poexp(-m*g*z/KT). In the last term in the force equation; i.e., the thrust, contains the exhaust gas speed u and the rate of change of the rocket's mass. To solve the problem we let, dx/dt=vx, dy/dt=vy, dm/dt=mass rate constant, dv x /dt=Fx/m, and dvy/dt=F y/m. In the simulation, the initial values of vx and v y can be change, as well as the friction coefficient c, the exhaust gas speeds ux, uy, and the mass rate constant . The density of the air, P, as well as the height from earth's surface is shown at the bottom. ]]> 25 true VARIABLE_EDITOR view true true size double xmin double xmax double ymin double ymax double t double dt double double double VARIABLE_EDITOR params true true earthRadius double earthSize double mountainx double mountainy double mountaindx double mountaindy double psize double x0 double y0 double vx0 double vy0 double m0 double earthm double gravityCst double xA double g double double VARIABLE_EDITOR projectile true true x double y double r double vx double vy double m double acst double ax double ay double a double showLoop boolean dtcst double v double cf double rho double rh double airm double T double BT double dz double cm double ux double uy double thrustx double thrusty double double CODE_EDITOR init true true ODE_EDITOR ODE true true t dt vx vy cm calcAx(x,y,vx) calcAy(x,y,vy) RungeKuttaFehlberg 1.e-5 CODE_EDITOR Evol Page true true CODE_EDITOR relation true true LIBRARY_EDITOR calcAx true true LIBRARY_EDITOR calcAy true true true Elements.Frame frameBasic true frameBasic border true 572,520 true Elements.Panel panel2 frameBasic south vbox 100,110 true Elements.Panel panel panel2 center grid:1,0,0,0 Elements.Button step panel clear _clearView() Elements.Button play panel play _play() Elements.Button reset panel init _initialize() Elements.Button pause panel pause _pause() Elements.CheckBox checkBox panel loop showLoop true Elements.Panel panel3 panel2 grid:2,0,0,0 Elements.Slider sliderVx panel3 center vx0 0.0 10.e3 _initialize() Vxo=0.0m/s;Vxo=-0.0m/s Elements.Slider SliderVy panel3 vy0 0.0 10.e3 _initialize() Vyo=0.0m/s;Vyo=-0.0m/s Elements.Slider ux panel3 ux -5000. 5000. ux =####.# Elements.Slider uy panel3 uy -5000. 5000. uy = ####.## Elements.Field Frict_coeff panel3 cf Frict_coeff = #.#### Elements.Field cm panel3 cm dm/dt = #.## Elements.Bar Air_density panel3 rh 0.0 1.3 air_density=#.##### green white Elements.Bar height panel3 dz 0.0 0.1*earthRadius height =# green white true Elements.Panel Panel frameBasic east grid:3,0,0,0 270,200 true Elements.PlottingPanel Velocity_vs_time Panel south Vy versus Vx Vx Vy true true Elements.Trace Trace Velocity_vs_time vx vy true blue NO_MARKER true true Elements.PlottingPanel y_vs_t Panel y_vs_t time y true true t y Elements.Trace Trace3 y_vs_t t y true NO_MARKER true Elements.PlottingPanel x_vs_t Panel x_vs_t time x true true t x Elements.Trace Trace4 x_vs_t t x true NO_MARKER true Elements.DrawingPanel drawingPanel frameBasic west true true xmin xmax ymin ymax true 300,200 Elements.Particle particleMountain drawingPanel mountainx mountainy mountaindx mountaindy gray Elements.Image image drawingPanel _data/earthrot2.gif 0. 0. earthSize-earthSize/50. earthSize-earthSize/50. false Elements.Dataset dataset drawingPanel 175 5 x y true red NO_MARKER Elements.Particle particle drawingPanel x y psize psize false black