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What is Projectile
Motion?

Instructional Objectives:
• Students will be able to:
– Define Projectile Motion
– Distinguish between the different types of
projectile motion
– Apply the concept to a toy car and measure its
velocity

Projectile Motion
• Two-dimensional motion of an object
– Vertical
– Horizontal

Types of Projectile
Motion
• Horizontal
– Motion of a ball rolling freely along a
level surface
– Horizontal velocity is ALWAYS
constant
• Vertical
– Motion of a freely falling object
– Force due to gravity
– Vertical component of velocity
changes with time
• Parabolic
– Path traced by an object accelerating
only in the vertical direction while
moving at constant horizontal velocity

• Launching a Cannon ball
Examples of Projectile
Motion

Equations
• X- Component
• Y- Component
• Vectors
x
y
v
v
v
v
f
f
yf
yf
xi
yi
2
x
y
v
v
i
i
v
v
yi
i
i
v
v
2
yi
xi
yi
gt
t
t
1
2
2gy
cos( )
sin( )
gt
2
Note: g= 9.8
m/s^2

Factors Affecting
Projectile Motion
• What two factors would affect projectile
motion?
– Angle
– Initial velocity
Initial Velocity
Angle

Class Exercise
An object is fired from the ground at 100
meters per second at an angle of 30
degrees with the horizontal
Calculate the horizontal and vertical
components of the initial velocity
After 2.0 seconds, how far has the object
traveled in the horizontal direction?
How high is the object at this point?

Solution
• Part a
• Part b
• Part c
v
v
ix
iy
v
ix
x
v
v
i
i
x
t
v
cos
sin
x
t
m
0
100 cos30 87 m
s
m
0
100 sin30 50m
s
s
87 m 2.0s 174m
s
2
1
t
50m
2.0s
9.8m
2
2 2.0s
1
y
viyt
g
2
s
2
s
s

Applications
Any Ideas?

LAB TIME!!!