Rigidbody.AddForce

function AddForce (force : Vector3, mode : ForceMode = ForceMode.Force) : void

Description

Adds a force to the rigidbody. As a result the rigidbody will start moving.

JavaScript
// Adds a force upwards in the global coordinate system

function FixedUpdate () {
rigidbody.AddForce (Vector3.up * 10);
}

function AddForce (x : float, y : float, z : float, mode : ForceMode = ForceMode.Force) : void

Description

Adds a force to the rigidbody. As a result the rigidbody will start moving.

JavaScript
// Adds a force upwards in the global coordinate system

function FixedUpdate () {
rigidbody.AddForce (0, 10, 0);
}

If you want to apply a force over several frames you should apply it inside FixedUpdate instead of Update.