Ball movement(noobie)

Unity Engine
1

Hi everyone,

I am trying to make my first game, but I have some problems with the speed of my player.
When I just move my player everything goes fine but as soon as press space to jump my player goes super fast:cry:
Can anyone point out what is wrong in my script?

Thanks in advance !

#pragma strict

var moveSpeed = 350;
var jumpHeight = 8;
var isFalling = false;

function Update () 
{
	//moving player;
	var moveHorizontal : float = Input.GetAxis("Horizontal");
	var moveVertical   : float = Input.GetAxis("Vertical");
	var movement : Vector3 = new Vector3 (moveHorizontal,0.0f,moveVertical); 
	rigidbody.AddForce(movement * moveSpeed * Time.deltaTime);
	//letting player jump
	if(Input.GetKeyDown(KeyCode.Space)  isFalling == false)
	{
	 	rigidbody.velocity.y = jumpHeight;
	}
	isFalling = true;
}

function OnCollisionStay ()
{
	isFalling = false;
}
2

Gravitational Potential Energy = mgh
Translational Kinetic Energy = ½mv²

Upward speed to achieve height h = sqrt(2gh)

3

And what does this mean, I am not that good at physics.

4

You’re going to have to learn some basic physics to write physics code, but for now:

rigidbody.velocity.y = Mathf.Sqrt(-2 * jumpHeight * Physics.gravity.y);
5

Thank you!