Freely Falling Bodies

A freely falling object is an object that moves under the influence of gravity only. Neglecting air resistance, all objects in free fall in the earth's gravitational field have a constant acceleration that is directed towards the earth's center, or perpendicular to the earth's surface, and of magnitude |$\vec{a}$| $\equiv$ g = 9.8 m/s ². If motion is straight up and down and we choose a coordinate system with the positive y-axis pointing up and perpendicular to the earth's surface, we describe the motion with Eq.(2.7), Eq.(2.8), Eq.(2.9) with a $\rightarrow$ - g , x $\rightarrow$ y .

Equations of Motion for the 1-d vertical motion of an object in free fall:

• v = v₀ - gt
• y = v₀t - ${\frac{1}{2}}$gt ²
• v ² = v₀² - 2gy

Note: Since the acceleration due to gravity is the same for any object, a heavy object does not fall faster than a light object.