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

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

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

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

Perpendicular components of motion are independent of each other

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

This may be a useful way to organize your data. Remember to solve x 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

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

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