How to calculate the distance of an object with velocity?

Instead of calculating distance between 1 object and another, can I calculate the distance between an object and another, can I calculate the distance using the ‘arch’ an object with dynamics has (like a mortar firing)? Here’s my example:

Most of the trajectory equations can also be found here. I’m not 100% sure whether you’re trying to get the horizontal distance or the arc length, so I’ve included both, and luckily Mathf has all the functionality we need:

private static float GRAVITY = 9.8067f;

public static float GetHorizontalDistance(float velocity, float launchAngle, bool degrees = false)
{
    // convert to radians if necessary
    if (degrees)
    {
        launchAngle *= Mathf.Deg2Rad;
    }

    return (velocity * velocity * Mathf.Sin(2.0f * launchAngle)) / GRAVITY;
}

public static float GetArcLength(float velocity, float launchAngle, bool degrees = false)
{
    // convert to radians if necessary
    if (degrees)
    {
        launchAngle *= Mathf.Deg2Rad;
    }

    // pre-calculate sine and cosine of launchAngle and square of velocity
    float sinAngle = Mathf.Sin(launchAngle);
    float cosAngle = Mathf.Cos(launchAngle);
    float vSquared = velocity * velocity;

    return (vSquared * (sinAngle + cosAngle * Mathf.Log((1.0f + sinAngle) / cosAngle))) / GRAVITY;
}

You may need to swap out the const GRAVITY for Unity’s value, depending on your usage case.