How to stop this infinite loop

I'm making a newtonian physics simulator as my computer science project but for some reason Unity keeps freezing as soon as I run the program and the whole application stops responding and the only way to stop it is through ending it with the task manager, however I suspect that the program has just entered an infinite loop as when I check the task manager it is still using up memory and the CPU. I really need this fixed as the deadline is in less than 2 weeks, any help on this would be greatly appreciated.

Here is the code I currently have for it, if anyone would like to use some of it for their own project then by all means use it.

UI:

 using System;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class UI : MonoBehaviour
 {
 
     public InputField massInput;
     public InputField ivInput;
     public InputField angleInput;
     public GameObject Ball;
     public GameObject Cube;
     public GameObject Car;
     public Text Error_Mass;
     public Text Error_IV;
     public Text Error_Angle;
     public Text Error_Dropdown;
     public static int mass;
     public static int initialVelocity;
     public static int angle;
     public Dropdown objects;
 
     //Use this for initialization
 
     void Start () {
         massCatch();
         ivCatch();
         angleCatch();
         objectCatch();
     }
 
     //This detects what object was chosen in the dropdown box and then destroys the game objects that were not chosen.
     public void objectCatch()
     {
         if (objects.value != 0)
         {
             Error_Dropdown.text = "";
         }
         if (objects.value == 1)
         {
             DestroyObject(Cube);
             DestroyObject(Car);          
         }
         else if (objects.value == 2)
         {
             DestroyObject(Ball);
             DestroyObject(Car);
         }
         else if (objects.value == 3)
         {
             DestroyObject(Ball);
             DestroyObject(Cube);
         }
     }
 
     public void angleCatch()
     {
         string angleInputString = angleInput.text;
         if (angleInputString == "")
         {
 
         }
         else
         {
             angle = Convert.ToInt32(angleInputString);
             if (angle > 0)
             {
                 Error_Angle.text = "";
             }
             else
             {
                 Error_Angle.text = "Please input suitable starting angle (0 - 90):";
             }
 
         }
     }
 
     //This takes the value inputted for the initial velocity and converts it into a variable to be used for calculations.
     public void ivCatch()
     {
         string velocityInputString = ivInput.text;
         if (velocityInputString == "")
         {
 
         }
         else
         {
             initialVelocity = Convert.ToInt32(velocityInputString);
             if (initialVelocity > 0)
             {
                 Error_IV.text = "";
             }
             else
             {
                 Error_IV.text = "Please input suitable initial velocity:";
             }
 
         }
     }
 
     //This takes the value inputted for the mass and converts it into a variable to be used for calculations.
     public void massCatch()
     {
         string massInputString = massInput.text;
         if (massInputString == "")
         {
 
         }
         else
         {
             mass = Convert.ToInt32(massInputString);
             if (mass > 0)
             {
                 Error_Mass.text = "";
             }
             else
             {
                 Error_Mass.text = "Please input suitable mass:";
             }
 
         }
     }
 
     //Update is called once per frame
     void Update()
     {
 
     }
 }

Forces:

 using System;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class Forces : MonoBehaviour {
 
     public int objectMass = 0;
     public int initialVelocity = 0;
     public int theta = 0;                                                                           //initial angle of movement set by user in the UI
     private double hori_U;
     private double vert_U;
     private double g = 9.8;                                                                         //gravity
     private double t;
     private double vert_V; 
     private double hori_V = 0;
     private double hori_S;
     private double vert_V_S;
     private double depth_S; 
     public double horizontalAcceleration = 0;
     public double verticalAcceleration = 0;
     public static double horizontalForce = 0;
     public static double verticalForce = 0;
     public static double vert_Sm = 0;
     public GameObject Ball;
     public GameObject Cube;
     public GameObject Car;
     public Dropdown Dropdown;
     public Vector3 movementUpdate;
 
 
     // Use this for initialization
     void Start() {
         objectSettings();
         
         
     }
 
     //This sets the initial starting position that all of the game objects will go to when they are picked
     public void objectSettings()
     {
         if (Dropdown.value == 1)
         {
             Ball.transform.position = new Vector3(16, 27, 285);
         }
         else if (Dropdown.value == 2)
         {
             Cube.transform.position = new Vector3(16, 27, 285);
         }
         else if (Dropdown.value == 3)
         {
             Car.transform.position = new Vector3(16, 27, 285);
         }
 
     }
 
     // Update is called once per frame
     void Update()
     {
         objectMass = UI.mass;
         initialVelocity = UI.initialVelocity;
         theta = UI.angle;
 
         //Horizontal and Verticle component variables
         hori_U = initialVelocity * Math.Cos(theta);                                                    //horizontal initial velocity
         vert_U = initialVelocity * Math.Sin(theta);                                                    //vertical initial velocity                                                               
         t = (2 * initialVelocity * Math.Sin(theta)) / 9.8;                                             //time
         vert_V = -1;                                                                                   //vertical current velocity
         hori_V = 0;                                                                                    //horizontal current velocity
         hori_S = hori_U * t;                                                                           //horizontal displacement (X)
         vert_V_S = (vert_U * t) + (0.5 * g * t * t);                                                   //vertical displacement used to solve the current vertical velocity
         depth_S = hori_S;                                                                              //depth displacement      (Z)
         do
         {
             vert_V = Math.Sqrt((2 * g * vert_V_S) + (vert_U * vert_U));
         } while (vert_V < 0);
         vert_Sm = -(vert_U * vert_U) / (2 * g);
         do
         {
             vert_V = Math.Sqrt((2 * g * vert_V_S) + (vert_U * vert_U));
         } while (vert_V >= 0);
 
         double vert_S = ((vert_U + vert_V) / 2) * t;
 
         hori_V = Math.Sqrt((2 * g * hori_S) + (hori_U * hori_U));                                                             
 
         float x = Convert.ToSingle(hori_S);                                                            //x co-ordinate for translation
         float y = Convert.ToSingle(vert_S);                                                            //y co-ordinate for translation
         float z = Convert.ToSingle(depth_S);                                                           //z co-ordinate for translation
 
         movementUpdate = new Vector3(x, y, z);
 
         horizontalAcceleration = (hori_V - hori_U) / t;
         verticalAcceleration = (vert_V - vert_U) / t;
         horizontalForce = objectMass * horizontalAcceleration;
         verticalForce = objectMass * verticalAcceleration;
 
         if (Dropdown.value == 1)
         {
             Ball.transform.Translate(movementUpdate);
         }
         else if (Dropdown.value == 2)
         {
             Cube.transform.position = movementUpdate;
         }
         else if (Dropdown.value == 3)
         {
             Car.transform.position = movementUpdate;
         }
     }
 
 }
 

CalcBox:

 using System;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class CalcBox : MonoBehaviour {
 
     public Text calculationBoxOutput;                   //calc box output
     public int mass = 0;
     public int initialVelocity = 0;
     public double hForce = 0;                                 //horizontal force of moving object
     public double vForce = 0;                                 //vertical force of moving object
     public double maximumVerticalDisplacement;
 
     // Use this for initialization
     void Start () {
         
     }
 
     // Update is called once per frame
     void Update () {
         mass = UI.mass;
         initialVelocity = UI.initialVelocity;
         hForce = Forces.horizontalForce;
         vForce = Forces.verticalForce;
         maximumVerticalDisplacement = Forces.vert_Sm;
         calculationBoxOutput.text = "Mass: " + mass + Environment.NewLine + "Initial Velocity: " + initialVelocity + Environment.NewLine + "Horizontal Force: " + hForce
             + Environment.NewLine + "Vertical Force: " + vForce + Environment.NewLine + "Peak of curve from start position: " + maximumVerticalDisplacement + " units"; 
     }
 }