Projectile motion describes the path of an object thrown or projected into the air. It has both horizontal and vertical motion. In the horizontal direction, the object maintains a constant velocity, but in the vertical direction it accelerates downward due to gravity. This results in a parabolic trajectory. The horizontal and vertical motions can be analyzed separately, with gravity only affecting vertical motion. The horizontal range of a projectile depends on its initial velocity and launch angle, with the maximum range achieved at 45 degrees.

1. Projectile Motion

2. What is a projectile?
• Any object that moves through the air or
space with an initial velocity and makes a
parabolic path is called a projectile

3. First…
• Let’s think about objects that move in a straight line…

4. Horizontal Motion
• If there were no gravity,
an object moving
horizontally (in the xdirection) would
continue to move
in a straight line
_________________

5. Vertical Motion
• If an object is
dropped
vertically (in the
y-direction), then
_______ causes
gravity
it to
• accelerate
___________
downwards

6. Projectile Motion
• Projectile motion is a ________________!
combination
constant
• In the x-direction, it continues to move at a __________
speed, but in the y-direction, it accelerate
___________downwards
because of gravity!

7. Take-Home Message!!!
INDEPENDENT
 For a projectile: THE X-VELOCITY IS _________________ OF
THE Y-VELOCITY!!!
 The speed in the x-direction doesn’t care what the speed in the
y-direction is!

8. Why?
gravity
• Remember that _____________is only pulling in one direction
right or left
(__________!) and nothing is pulling ________________
down
• If there were no gravity, a projectile would go
straight
__________forever:

9. Velocity Vectors
• Remember that velocity has a ____________, so it can be
direction
represented using ____________!
vectors
• We can break down the velocity into separate x- and ycomponents:

10. Velocity Vectors
• Let’s examine the x and y velocity vectors for a projectile:
• Its x-velocity staysconstant
__________and its y-velocity
increases
_____________.

11. Just like in free-fall:
Y-Velocity
 Velocity in the y-directiondecreases
___________on the way up, and
increases
____________on the way down
 At the top of the path, the y-velocity is always zero
______
 Velocity on the way up equals
________velocity on the way down
height
when you reach the same _________

12. *Checkpoint Question 1*
• If you were walking at a constant velocity with
a baseball and threw it up into the air while
you were walking, would it fall
– A. in front of you
– B. behind you
– C. right back into your hands?
• Why??

13. Answer!
• Its y-velocity is different than yours, but its x-velocity stays
the same as you. It should land back into your hands!

14. **Checkpoint Question 2**
• An airplane is carrying a bomb and traveling
with a velocity of 1,100 mph east. If it
releases its bomb and continues at that
velocity, will the bomb land:
– A. Directly underneath the plane
– B. Behind the plane
– C. Ahead of the plane

15. Answer!
• If they’re going at the same x-velocity, it will land directly
beneath the plane!

16. ***Checkpoint Question 3***
• Suppose two balls released
from the same height: one is
dropped from rest, and the
other is thrown horizontally.
Which will hit the ground first?
Why?
• They will hit at the same time,
because they are both being
pulled by gravity at the same
rate! Only one will have a
greater x-range.

17. X-Range and Max Vertical Height
• Your x- distance is called your __________and your
range
height
y-distance is called your __________.
• Your range and height depend on:
angle
– The _______ that the projectile is launched at and
velocity
– The __________it is launched at

18. Angle
• Increasing your angle increases your range until you reach
45°.
• 45° to 90°, increasing your angle decreases your range.

19. Initial Velocity
• The greater the initial velocity of a projectile,
farther
the ____________it will go:

20. The trajectory of an object depends on how
fast it is moving horizontally and how long
gravity acts on it for.
Earth

21. The trajectory of an object
depends on how fast it is
moving horizontally and how
long gravity acts on it for.
Small horizontal velocity
Earth

22. The trajectory of an object
depends on how fast it is moving
horizontally and how long gravity
acts on it for.
Medium horizontal velocity
Earth

23. The trajectory of an object depends on how
fast it is moving horizontally and how long
gravity acts on it for.
Fast horizontal velocity
Earth

24. Projectile Motion
A projectile is always falling.
The faster it moves horizontally, the farther
away it will be when it hits the ground.
Slow
Medium
Fast