Projectile motion based off angle

Question

I was using this code to hit an object that is moving horizontally(from right to left) and player on the left is throwing bullets to hit the object.But, what I am finding difficult is projectile motion based off angle(since the object that is to be hit is moving and I can not just keep throwing projectile at the same angle).

Here is what I was using that does not seem to work since the angle is fixed.

How to modify this code so that the angle is changed and not the velocity

IEnumerator project()
    {    yield return new WaitForSeconds(0.25f);
        float target_Distance = Vector3.Distance(mytransform.position, target.position);
        // Calculate the velocity needed to throw the object to the target at specified angle.
        float projectile_Velocity = target_Distance / (Mathf.Sin(2 * firingAngle * Mathf.Deg2Rad) / gravity);

        // Extract the X  Y componenent of the velocity
        float Vx = Mathf.Sqrt(projectile_Velocity) * Mathf.Cos(firingAngle * Mathf.Deg2Rad);
        float Vy = Mathf.Sqrt(projectile_Velocity) * Mathf.Sin(firingAngle * Mathf.Deg2Rad);

        // Calculate flight time.
        float flightDuration = target_Distance / Vx;

        // Rotate projectile to face the target.
        mytransform.rotation = Quaternion.LookRotation(target.position - mytransform.position);

        float elapse_time = 0;

        while (elapse_time < flightDuration)
        {
            mytransform.Translate(0, (Vy - (gravity * elapse_time)) * Time.deltaTime, Vx * Time.deltaTime);

            elapse_time += Time.deltaTime;

            yield return null;
        }

Answer 1

Okay, I understood. I needed to initialize the prefab at the time of shooting. So, I found it appropriate to do it in the source script rather than the bulletprefab itself. Here is the code:

Projectile motion In unity 3D

Hope that helps!