1. World Record Free Fall
After flying to an altitude of 39,045 meters (128,100 feet) in a helium-filled balloon, Felix Baumgartner 

2. Free Fall
Definition-motion under the influence of gravitational force only

3. Example of free fall Dropping a ball? Throwing a ball? Yes
Yes, once it leaves your hand

4. It is a force of attraction

5. For medieval science, freely falling objects moved too quickly and the clocks could not record quickly enough .
So Galileo devised to slow down the motion by replacing the
falling object with a ball rolling down a gently inclined plane.

6. Up on a graph is +, down -...so g= -9.8 m/s², downward
little “g”
Little g is known as the acceleration due to gravity
Magnitude is 9.8
Up on a graph is +, down -...so g= -9.8 m/s², downward

7. Physics misconception
Galileo did not, as is popularly believed, state that the objects would hit the ground at the same time – he understood air resistance. He did understand that without air resistance, the objects would fall at exactly the same rate.

8. On the moon

9. The vertical velocity is dependent upon the time for which it has fallen and increases by 9.8m every second
Time (s) Velocity (m/s)

10. All objects always accelerate at the same rate
Experience tells you that objects speed up (or accelerate) as they fall
All objects always accelerate at the same rate
(when we ignore air resistance)

11. How far will an object drop?
xy=x₀+v₀t+1/2at²
xy= ½ gt²
I drop a rock off of a bridge, and 4.2 s later, I hear a splash. What is the height of the bridge?
X = ½ (9.8 m/s²) (4.2 s)²
= 86 m

12. Free Fall with Upward Motion
It experiences a downward acceleration
The object spends half its time traveling up; half traveling down.
At the top, velocity is 0

13. 2) A ball is thrown upward
The ball is thrown upward with an initial velocity of 10 m/s.
What is it’s maximum height?
v²= v₀²+ 2a(x-x₀)
v²= v₀²+ 2g(x)

14. Free Fall with Upward Motion
Homer Hickham used this fact to determine how high his rocket went  and that the rocket boys didn’t start the fire in Welch

15. October Sky

16. Myth Busters