/// <summary>
/// Check Static Friction
/// </summary>
/// <param name="parallelNetForce">the net force vector projected parallel to the surface</param>
/// <param name="normalForce">the normal force vector</param>
/// <param name="coefficientOfFriction">the coefficient of static friction</param>
/// <returns>if the force is sufficient to overcome static friction</returns>
public static bool CheckStaticFriction(Vector3D parallelNetForce, Vector3D normalForce, float coefficientOfFriction)
{
return ((coefficientOfFriction * normalForce.GetMagnitude()) < parallelNetForce.GetMagnitude());
}
/// <summary>
/// Kinetic Friction
/// </summary>
/// <param name="velocity">velocity vector</param>
/// <param name="normalForce">normal force vector</param>
/// <param name="coefficientOfFriction">the coefficient of kinetic friction</param>
/// <returns>kinetic friction force vector</returns>
public static Vector3D KineticFriction(Vector3D velocity, Vector3D normalForce, float coefficientOfFriction)
{
return ((-coefficientOfFriction * normalForce.GetMagnitude()) * (!velocity));
}
static void Orbit()
{
//giant block o' variables
Console.Write("Input initial speed in km/s: ");
Vector3D velocity = new Vector3D(Convert.ToSingle(Console.ReadLine()) * 1000f, 0); //m/s
Vector3D position = new Vector3D(0, 6778000f); //m
float massOfSpacecraft = 225f; //kg
float inverseMassOfSpacecraft = 1 / massOfSpacecraft; //1/kg
float massOfEarth = 5.98e24f; //kg
float radiusOfEarth = 6378000f; //m
float atmosphereRadius = 6478000f; //m
int timeStep = 10; //s
float arbitrarySmallAmount = 1f; //m
float altitude = (position.Y - radiusOfEarth) / 1000f; //km
float speed = velocity.X / 1000f; //km/s
float totalEnergy = (massOfSpacecraft * speed * speed * 500000f) + GravityPE(position.GetMagnitude(), massOfSpacecraft, massOfEarth); //N
Vector3D acceleration = inverseMassOfSpacecraft * GravityPEForce2D (position, massOfSpacecraft, massOfEarth, arbitrarySmallAmount); //m/(s^2)
Console.WriteLine("Time: {0:N}s, Altitude: {1:N2}km,\nSpeed: {2:N2}km/s,\nTotal energy: {3:N2}N Acceleration: " + acceleration.PrintRect(), 0, altitude, speed, totalEnergy);
//start simulation loop
for (int time = 0; time < 36000 && position.GetMagnitude() > atmosphereRadius; time += timeStep) //time is in seconds
{
position += velocity * timeStep; //update position
velocity += acceleration * timeStep; //update velocity
acceleration = inverseMassOfSpacecraft * GravityPEForce2D(position, massOfSpacecraft, massOfEarth, arbitrarySmallAmount); //update acceleration
//calculate and display output
altitude = (position.GetMagnitude() - radiusOfEarth) / 1000f;
speed = velocity.GetMagnitude() / 1000f;
totalEnergy = (massOfSpacecraft * speed * speed * 500000f) + GravityPE(position.GetMagnitude(), massOfSpacecraft, massOfEarth);
Console.WriteLine("Time: {0:N}s, Altitude: {1:N2}km,\nSpeed: {2:N2}km/s,\nTotal energy: {3:N2}N", time, altitude, speed, totalEnergy);
}
if (position.GetMagnitude() <= atmosphereRadius)
{
Console.WriteLine("Crashed into atmosphere! Go faster next time!");
}
}
