1. Free Fall Physics Created by K.Rick

2. What is free fall? Motion under the influence of gravitational force only. When you free fall do you fall at a constant rate?

3. Constant Acceleration Look at the data: Use the equation above to solve for the acceleration of an object in free fall. Time (s)Velocity (m/s) 00 110 220 330 440 What does the 10 m/s 2 represent? a = Δv / Δt a = v 2 – v 1 t 2 – t 1 Is there a relationship between velocity and time because of this acceleration?

4. Constant Acceleration Time (s)Velocity (m/s) 00 110 220 330 440 Can you write this relationship as an equation? Is there a relationship between velocity and time because of this acceleration? v = g t

5. How Fast? To find the instantaneous speed of an object in free fall use the following equation: V = g t

6. Check Your Understanding : What would be the speedometer reading on a falling rock 4.5 seconds after it drops from rest? How about 8 seconds?

7. How far? Time (s)Distance (m) 00 15 220 345 480 5125 Can you find the mathematical relationship between time and distance? (hint: don’t forget “g”!) d = ½ g (t 2 ) Find the distance an object will fall after 8 seconds of free fall.

8. How long? Rearrange the distance equation to solve for the time the object falls? T = 2 d / g How long has this skydiver free fallen if he falls for 80 meters? d = ½ g (t 2 )

9. Check Yourself : An object is dropped from rest and falls freely. After 6 seconds, calculate its instantaneous speed and distance fallen. Instan. Speed V = g t V= 10 m/s 2 * 6s V = 60 m/s Distance d = ½ g t 2 d = ½ 10m/s 2 * 6s 2 d = 180 m

10. Double Check Yourself : An object is dropped from rest and falls freely. After 8 seconds, calculate its instantaneous speed and distance fallen. Distance d = ½ g t 2 d = ½ 10m/s 2 * 8s 2 d = 320 m Instan. Speed V = g t V= 10 m/s 2 * 8s V = 80 m/s

11. More Practice An object falls a distance of 125m. What is its instantaneous speed just before it hits the ground? (hint: find t then find v)

12. FYI: DaVinci’s Parachute This is DaVinci’s 1493 parachute design This is the modern reproduction of his sketch. His design is highly functional!