Vector3 and power

How does the vector 3 statement translate to a force? The following code launches a projectile and it does succumb to gravity. I would like to be specific about the mass, angle and force applied, and the let unity do the rest :). Am I on the right path? Thanks for any comments.

var myCounter = 0;

function FixedUpdate ()
{
        // Apply force for 15 somethings
    while ( myCounter < 15) {
        var power: Vector3 = Vector3(0,25000,25000);
            rigidbody.AddForce(power, ForceMode.Force); 
        myCounter++; 
    }
}   

The length of the vector is what you want.

You can calculate the angle between the forward vector and your target vector with this

If you want to specify the direction of the vector and then apply a specific length first you find the normalised vector (unit length) and then simply multiply by the power you want

If you want to enter a specific angle you can set the rotation to be horizontal and then use the rotate function to tilt the angle up