Projectile Motion

1
Projectile Motion

• Chapter 3

2
Projectile Motion

• An object is given an initial velocity (vo), then
  the path is determined by the force of gravity.
  Since gravity is the only force acting on the
  object in free fall, the object accelerates in
  the y direction and has a constant velocity in
  the x direction since air resistance is
  neglected.

3
Types of Projectiles

• Angular

Horizontal
Projectile Motion Applet
4
Equations with Multiple Components

• Inferred information
• At max height vy 0 and vx v
• vox vx because ax 0
• For a horizontal projectile voy 0
• tan ? vy/vx
• v vvx2 vy2

5
Horizontal Equations

• Kinematics equations tailored for the two
  dimensions of motion
• x-direction (ax 0 for projectiles neglect air
  resistance)
• vx vox
• vox vocos ?
• x 1/2(vox vx)t
• x voxt

6
Vertical Equations

• y-direction (ay -9.8 m/s2 for a projectile)
  voy vosin ?
• vy voy ayt
• vy2 voy2 2ayy
• y 1/2(voyvy)t
• y voyt 1/2ayt2

7
Range Equation

• Range equation only applicable when the object
  starts and stops at the same horizontal level.
• R vo2sin(2?)
• g

8
Definition of Variables

• vox horizontal component of the original
  velocity in m/s
• voy vertical component of the original velocity
  in m/s
• vx horizontal component of velocity at a later
  time in m/s
• vy - vertical component of velocity at a later
  time in m/s
• x horizontal distance in meters
• y vertical distance in meters
• t time in seconds
• vo original vector velocity in m/s
• v vector velocity at some later time in m/s