Projectile Motion
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JOHN ANTHONY TEVESProjectile Motion
Uploaded by
JOHN ANTHONY TEVESPROJECTILE
MOTION
LEARNING OBJECTIVES
1. Describe projectile motion qualitatively.
2. Label a diagram illustrating projectile
motion by indicating the range, height,
trajectory, initial horizontal velocity, and
initial vertical velocity.
3. Recognize examples of projectile motion
Which of the three situations is/are more
likely to happen in real-life?
Projectile motion
Projectile motion is the motion of an object thrown
(projected) into the air. After the initial force that
launches the object, it only experiences the force
of gravity. The object is called a projectile, and its
path is called its trajectory.
The motion of an object thrown or
projected into the air, subject only to
acceleration as a result of gravity. The
applications of projectile motion in
physics and engineering are numerous.
Some examples include meteors as they
enter Earth’s atmosphere, fireworks, and
the motion of any ball in sports.
• In a Projectile Motion, there are two
simultaneous independent rectilinear
motions:
Vertical Motion - Along y-axis: uniform
acceleration, responsible for the vertical
(downwards) motion of the particle.
Horizontal Motion - Along the x-axis: uniform
velocity, responsible for the horizontal
(forward) motion of the particle.
Vertical Motion
Projectile is controlled by the force of gravity.
This means that there is an unbalanced force
acting on the object and so the object will
accelerate downwards. This acceleration is
9⋅8 m/s2 (the gravitational field strength on
Earth).
Horizontal Motion
The result of the tendency of any object in
motion to remain in motion at constant velocity.
Due to the absence of horizontal forces, a
projectile remains in motion with a constant
horizontal velocity. Horizontal forces are not
required to keep a projectile moving horizontally.
The only force acting upon a projectile is gravity.
Comparing Free Fall and Projectile
• The most important concept in projectile motion is
that horizontal and vertical motions are independent,
meaning that they don’t influence one another.
• Figure 1 compares a cannonball in free fall to a
cannonball launched horizontally in projectile motion.
You can see that the cannonball in free fall falls at the
same rate as the cannonball in projectile motion. Keep
in mind that if the cannon launched the ball with any
vertical component to the velocity, the vertical
displacements would not line up perfectly.
• We will call the horizontal axis the x-axis and the vertical axis the y-
axis. For notation, d is the total displacement, and x and y are its
components along the horizontal and vertical axes. The magnitudes of
these vectors are x and y, as illustrated in Figure 2.
REMEMBER:
A projectile is any object upon which the only force is gravity,
Projectiles travel with a parabolic trajectory due to the influence of
gravity,
There are no horizontal forces acting upon projectiles and thus no
horizontal acceleration,
The horizontal velocity of a projectile is constant (a never changing in
value),
There is a vertical acceleration caused by gravity; its value is 9.8 m/s
2, down,
The vertical velocity of a projectile changes by 9.8 m/s each second,
The horizontal motion of a projectile is independent of its vertical
motion.
EVALUATION
DIRECTIONS: Choose the letter of the BEST answer.