1. Free Fall 3.3

2. Free Fall Where friction is negligible and the falling action is due to gravity alone.

3. Acceleration Due to Gravity Galileo Galilei about 400 years ago worked with gravity Ignored effects of air resistance Used an inclined plane to “dilute” gravity

4. Findings All freely falling objects have the same acceleration Mass didn’t matter Original height didn’t matter Initial velocity didn’t matter g = 9.8 m/s 2

5. Remember that 9.8 m/s 2 is the magnitude of the gravity The negative or positive sign indicates direction Down is usually negative Up is usually positive But gravity always acts down

6. Determine your coordinate system and stick with the same system. Decide whether up is positive or negative.

7. Throwing a Ball Up Acceleration Initial velocity compared to final velocity Total displacement Total distance

8. Equations The equations are the same. The a will be 9.8 m/s 2