1. Free-fall lab

2. Acceleration due to gravity
Gravity (on Earth) pulls
objects downward at a
rate of 9.8 m/s2
ignoring air resistance

3. Pre-lab example
Sean is standing on top of a building that is 25 meters tall and asks me to throw him a can of Sprite. I am hesitant because I know that I can’t throw very high, so I test how high I can throw with a tennis ball first. I throw my tennis ball up and time how long it is in flight. The time the ball is in the air is 3.9 seconds. Should I attempt to throw the Sprite to Sean?

4. Draw it out
d = ½ gt2
Time = 3.9 s

5. Let’s see if we were right
Oops

6. Pre-lab Problems

7. Part 1 – What is the acceleration due to gravity?
Timer
d = 5.6 m

8. Part 2 – What is your reaction time?
Don’t forget to record the DISPLACEMENT of the ruler, not necessarily the number you read on the meter stick

9. Part 3 – How high can you throw?
Here’s some free advice: Try to throw the ball straight up and down!
Timer

10. Images http://www.physicsclassroom.com/Class/1DKin/U1L5d6.gif