Rigidbody.AddForceAtPosition
AddForceAtPosition(force: Vector3, position: Vector3, mode: ForceMode = ForceMode.Force): void;
Description

Applies force at position. As a result this will apply a torque and force on the object.

For realistic effects position should be approximately in the range of the surface of the rigidbody. This is most commonly used for explosions. When applying explosions it is best to apply forces over several frames instead of just one. Note that when position is far away from the center of the rigidbody the applied torque will be unrealistically large.
	function ApplyForce (body : Rigidbody) {
		var direction : Vector3 = body.transform.position - transform.position;
		body.AddForceAtPosition(direction.normalized, transform.position);
	}