The Ballistic Range (Earth Gravity) calculator computes the maximum range (horizontal distance) traveled by an object based on the ballistic flightheight (h) above the horizon of the launch point, initial velocity (V) of the object, and angle of launch (?), and the vertical acceleration (g) attributed to gravity on the surface of the Earth . 

INSTRUCTIONS: Choose the preferred units and enter the following:

• (h)  This is the initial height of the launch point above the plane.
• (V)  This is the initial velocity of the object that is launched (e.g. muzzle velocity from the gun or cannon)
• (?)  This is the launch angle above the horizon.

Max Range (x): The calculator returns the maximum distance down range (x) in meters.  However, this can be automatically converted to other distance units (e.g. miles or kilometers) via the pull-down menu.

Related Calculators:

• Maximum Altitude:  This is the maximum altitude achieved in free ballistic flight.

The Math / Science

The Ballistic Range equation:

                              `R = ((V * sin(theta) + sqrt( (V *sin(theta))^2 + (2*g*h)))" /  "g) * cos(theta)*V)`

This formula calculates the range (horizontal distance) traveled by an object based on the  height (h) above the horizon of the launch point, initial velocity (V) of the object, and angle of launch (theta), and the vertical acceleration (g). 

The Ballistic Range equation calculates the horizontal displacement (distance) of an object in free flight.  It only takes into account the initial velocity and launch angle (also knows as the loft) and the effects of gravity through an acceleration towards the ground.  This formula does not take into account other factors such as drag (see below).  A default is provided for the acceleration due to gravity of 9.80665 m/s² which is mean acceleration (at all latitudes) for sea level on Earth.

Acceleration Due to gravity

The force of gravity pulls masses towards each other.  In the case of small objects (e.g. you, an arrow or the Space Shuttle) verses planetary objects (e.g. the Earth or Moon), the difference in masses result in a negligible acceleration of the large object toward the small and small object accelerating toward the center of mass of the large object.  Acceleration due to gravity changes based on the mass of the object (e.g. the Earth 9.8 m/s² verses the moon1.6 m/s²) and the distance from the center of mass.  For example, since the Earth is not a perfect sphere, and more closely represented as an oblate spheroid, acceleration due to Earth gravity as Sea Level is more accurately calculated based on latitude: click here -> The international gravity formula provide an acceleration due to gravity based on latitude.  CLICK HERE for the acceleration due to gravity for the other planets in the solar system. 

See Also

• Travel Time
• International Gravity Equation
• Force of Earth's Gravity
• Force of Drag

History

Galileo was the first individual to correctly describe the motions of a projectile in free-fall¹.  His discoveries were published in 1638.  Until that time, the accepted view of ballistics was based on Aristotle's descriptions.

Usage

This equation computes the ballistic range of a projectile launched from a chosen height above the local plane and uses the simplified model in which gravitational attraction is the only force exerted on the projectile. 

See also

• Ballistic Range
• Ballistic Travel Time
• Ballistic Max Height

1. ^ http://www.nature.com/scientificamerican/journal/v228/n5/pdf/scientificamerican0573-84.pdf