Air resistance is the force exerted by air on a moving object, acting in the opposite direction of the object's motion. The larger the surface area of an object, the greater the air resistance, which is why leaves fall more slowly than acorns of similar mass. As an object falls through air, air resistance increases until it balances the force of gravity, at which point the object reaches its terminal velocity and stops accelerating further downward.

1. Air Resistance

2. If only gravity is present, all objects accelerate at 9.8 m/s 2 Air resistance- the force air exerts on a moving object. This force acts in the opposite direction to the object’s motion. Air resistance pushes up as gravity pulls an object down.

3. Ex: The larger the surface area of objects, the greater amount of air resistance on it. This is why a leaf falls more slowly than an acorn. Terminal Velocity- the highest velocity that will be reached by a falling object.

4. Ex: As an object falls through the air, air resistance gradually increases until it balances the pull of gravity. When this happens, the falling object will stop accelerating. This is the terminal velocity.

5. Falling Object Equation #1 Variable Ending Units d= distance meters (m) a= acceleration m/s 2 t= time seconds

6. Falling Object Equation #1 d = ½ at 2

7. Falling Object Equation #2 Variable Ending Units v= velocity m/s a= acceleration m/s 2 t= time seconds

8. Falling Objects Equation #2 v= a X t a= v / t t= v / a v . . . . X a t