When an object is dropped, the speed with which it falls continues to increase. Ignoring air resistance, its height [i][b]h[/b][/i] can be approximated by the [b]falling object model[/b].[br][br][math]h=-16t^2+s[/math]   [color=#1155cc]Falling object model[br][/color][br]Here [b][i]h[/i][/b] is measured in feet, [b][i]t[/i][/b] is the number of seconds the object has fallen, and [b][i]s[/i][/b] is the initial height from which the object was dropped.[br][br]The object's increase in speed is due to Earth's gravitational pull. On a planet whose gravitational pull is different from that of Earth, the factor [math]-16[/math] would be replaced by another constant.