Object won fall of the platform in Unity - unity3d

Question

So i made an ball(player) which moves forward on it's own with script. I want to make that ball act like a normal ball. when it riches the edge of platform it won't fall off. Basicaly it stops on the edge. Here's my image:
Here's my controller script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class SwerveInputSystem : MonoBehaviour
{
private float _lastFrameFingerPositionX;
private float _moveFactorX;
public float MoveFactorX => _moveFactorX;
void Start(){
}
// Update is called once per frame
void Update()
{
if (Input.GetMouseButtonDown(0))
{
_lastFrameFingerPositionX = Input.mousePosition.x;
}
else if (Input.GetMouseButton(0))
{
_moveFactorX = Input.mousePosition.x - _lastFrameFingerPositionX;
_lastFrameFingerPositionX = Input.mousePosition.x;
}
else if (Input.GetMouseButtonUp(0))
{
_moveFactorX = 0f;
}
}
}
This is Second script:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class PlayerController : MonoBehaviour{
private SwerveInputSystem _swerveInputSystem;
[SerializeField] private float swerveSpeed = 5f;
[SerializeField] private float maxSwerveAmount = 1f;
[SerializeField] private float verticalSpeed;
void Start(){
_swerveInputSystem = GetComponent<SwerveInputSystem>();
}
void Update(){
float swerveAmount = Time.deltaTime * swerveSpeed * _swerveInputSystem.MoveFactorX;
swerveAmount = Mathf.Clamp(swerveAmount, -maxSwerveAmount, maxSwerveAmount);
transform.Translate(swerveAmount, 0, 0);
float verticalDelta = verticalSpeed * Time.deltaTime;
transform.Translate(swerveAmount, verticalDelta, 0.1f);
}
}

Answer 1

EDITED: Adjusted the answer since we now have some source code.
You are positioning the player directly (using its transform) which will mess up the physics. The purpose of a rigidbody is to let Unity calculate forces, gravity, and so on for you. When you are using physics, and you want to move an object you have three main options:
Teleporting the object to a new position, ignoring colliders and forces like gravity. In this case use the rigidbody's position property.
_ourRigidbody.position = new Vector3(x, y, z);
Moving the object to the new position, similar to teleporting but the movement can be interrupted by other colliders. So, if there is a wall between the object and the new position, the movement will be halted at the wall. Use MovePosition().
_ourRigidbody.MovePosition(new Vector3(x, y, z));
Adding some force to the object and letting the physics engine calculate how the object is moved. There are several options like AddForce() and AddExplostionForce(), etc... see the Rigidbody component for more information.
_ourRigidbody.AddRelativeForce(new Vector3(x, y, z));
In your case you can simply remove the transsform.Translate() calls and instead add some force like this:
//transform.Translate(swerveAmount, 0, 0);
//transform.Translate(swerveAmount, verticalDelta, 0.1f);
Vector3 force = new Vector3(swerveAmount, verticalDelta, 0);
_ourRigidbody.AddForce(force);
We can get the _ourRigidbody variable in the Awake() or Start() method as normal. As you can see I like the Assert checks just to be safe, one day someone will remove the rigidbody by mistake, and then it is good to know about it...
private SwerveInputSystem _swerveInputSystem;
private Rigidbody _ourRigidbody;
void Start()
{
_swerveInputSystem = GetComponent<SwerveInputSystem>();
Assert.IsNotNull(_swerveInputSystem);
_ourRigidbody = GetComponent<Rigidbody>();
Assert.IsNotNull(_ourRigidbody);
}

Answer 2

One likely reason your Rigidbody is not being affected by gravity is due to having the field isKinematic checked to on. From the Rigidbody docs, when toggling on isKinematic,
Forces, collisions or joints will not affect the rigidbody anymore.
The rigidbody will be under full control of animation or script
control by changing transform.position
As gravity is a force and no forces act on the object when this setting is checked, your object will not fall when it is no longer on the platform. A simple solution is to uncheck this box.