Free Fall & 1-Dimensional Motion

What was the purpose of Galileo's Free Fall Experiment?

To challenge the Aristotelian belief that heavier bodies fall faster, hypothesizing that all bodies fall at the same rate in the absence of air resistance.

What is Free Fall?

Motion of an object moving freely near the surface of the Earth in the absence of air resistance.

What is the acceleration of a free-falling object near Earth's surface?

A constant acceleration directed downwards (towards Earth's center) with magnitude g = 9.81 m s⁻².

What are the Kinematics Equations for Free Fall (taking up as positive)?

ay = -g = -9.81 m s⁻², vy = uy + ay t, sy = uy t + ½ ay t², vy² = uy² + 2 ay s_y.

What are the four Kinematic Equations for One-Dimensional Motion?

v = u + at, s = ½ (u+v)t, s = ut + ½ at², v² = u² + 2as.

What are the conditions for using these four Kinematic Equations?

Apply only to motion in a straight line with constant acceleration.

What are the components of acceleration for free-falling bodies in air (without air resistance)?

Constant vertical acceleration (a_y = g = 9.81 m s⁻²) directed downwards; zero horizontal acceleration (a_x = 0).