1. Projectile Motion: Physics of Baseball September 22, 2010
PHYS16 – Lecture 7
Projectile Motion: Physics of Baseball
September 22, 2010

2. Key Concepts: Physics 2D Motion
Constant acceleration
Independent in x and y
Relative Motion
Projectile Motion
Definition
Solving problems using kinematic equations
Max range and height

3. Projectile Motion
Projectile = a propelled object that travels through the air
Projectile motion or not?
Throw up (Yes), throw straight out (Yes), Roll on ground (No)

4. Kinematic Equations X Y

5. Separate and Solve
Pitcher winds up and throws the ball, then what happens?
Ball experiences free fall in y and constant motion in x
/pages/pm_homeage.html

6. Separate and Solve
Batter hits the ball up at an angle, then what happens?
Ball experiences free fall in y and constant motion in x
/cobb_ty_batting_1.jpg

7. What does that mean?
If I drop an object and throw an object do they land at the same time? (Yes)
Where should I aim if I shoot an object and an object drops at the same time? (At the object)
Shoot the Monkey Demo!

8. What does that mean?
If I throw two objects straight out with different speeds, do they land at the same time?
Yes!
Quarter/Ruler Demo

9. What does that mean? At the start… At the top of the arc…
When it is back at the same height…

10. What does that mean? At the start… At the top of the arc…
When it is back at the same height…

11. Optimizing your Batting Skills
What is the best angle to hit the ball at?
Let’s find max height and range
Measure projectile motion for Ball launcher
Derive Equations
No air resistance -> 45 degrees is the best

12. Summary For 2D motion x and y are independent so separate and solve
Projectile Motion – objects propelled through air
Initial x velocity but no x acceleration
Initial y velocity, acceleration due to gravity
Top of arc, y velocity is zero