1. For each diagram below, create a free diagram of the ball at the top of the path
As you view the following video and animation think about the forces in your free body diagrams 2-D Motion

2. Independence of Motion
Notice that the veridical motion of the projected ball is identical to the vertical motion of the falling ball
Notice that the projected ball travels forward at constant speed

3. Horizontal Component of Velocity
Newton's 1st Law
Is constant
Not accelerated
Not influenced by gravity
Follows equation:
dx = Vixt + 1/2axt2

4. Vertical Component of Velocity
Newton's 2nd Law
Undergoes accelerated motion
Accelerated by gravity (9.8 m/s2 down)
Vfy = Viy + at
dy = Viyt + 1/2ayt2
Vfy2 = Viy2 + 2aydy
For all y-direction projectile equations
a=g

5. Perpendicular components of motion are independent of each other

6. Independence of Motion
Please visit the Physics Zone Projectile Motion Lesson “Archer in Truck: Proof III”
at sciencejoywagon.com to access this video.

7. This may be a useful way to organize your data. Remember to solvex y Vi Vf v v a
 d
 t
This may be a useful way to organize your data. Remember to solve
x variables with x variables
and
y variables with y variables….
TIME links the x and y variables

8. Projectile fired at an angle
As you view this video, notice the independence of motion.
Notice that the vertical acceleration is downward and constant
The ball “slows” during ascent and “speeds up” during descent
When angles are involved, the appropriate components of velocity must be used and the sign used to indicate the direction of velocity and acceleration is very important

9. A bouncing ball captured with a stroboscopic flash at 25 images per second. MichaelMaggs Edit by Richard Bartz