PROJECTILE 
MOTION 
Sonia
Content 
Definition of Projectile 
Definition of Projectile Motion 
Types of Projectile Motion 
Examples of Projectile motion 
Derivation of projectile motion in 2-D 
Factors Affecting Projectile Motion
Definition Of Projectile 
A projectile is any object that once projected or dropped 
continues in motion by its own inertia and is influenced only by 
the downward force of gravity. 
By definition, a projectile has a single force that acts upon it - 
the force of gravity. If there were any other force acting upon 
an object, then that object would not be a projectile. Thus, the 
free-body diagram of a projectile would show a single force 
acting downwards and labeled force of gravity (or simply Fgrav). 
Regardless of whether a projectile is moving downwards, 
upwards, upwards and rightwards, or downwards and 
leftwards, the free-body diagram of the projectile is still as 
depicted in the diagram at the right. 
Fgrav 
Free-body diagram 
of a projectile
Definition Of Projectile 
Motion 
Projectile motion is a form of motion in which an object or particle (called a 
projectile) is thrown near the earth's surface, and it moves along a curved path 
under the action of gravity only. Example: Parabolic water trajectory
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
Examples Of Projectile Motion 
Launching a Cannon ball
Examples Of Projectile Motion 
Object thrown upward from a car moving in a horizontal direction
Derivation Of Projectile Motion in 2-D 
The initial velocity 
If the projectile is launched with an initial velocity , then it 
can be written as 
The components and can be found if the angle, is known: 
If the projectile's range, launch angle, and drop height are 
known, launch velocity can be found using Newton's 
formula 
The launch angle is usually expressed by the symbol theta, 
but often the symbol alpha is used. 
Initial velocity of 
parabolic throwing 
Components of initial 
velocity of parabolic 
throwing
Derivation Of Projectile Motion in 2-D 
Kinematic quantities of projectile motion 
In projectile motion, the horizontal motion and the vertical motion are 
independent of each other; that is, neither motion affects the other. 
Acceleration 
Since there is no acceleration in the horizontal direction, the velocity in the 
horizontal direction is constant, being equal to 
The vertical motion of the projectile is the motion of a particle during its free 
fall. Here the acceleration is constant, being equal to 
The components of the acceleration are:
Derivation Of Projectile Motion in 2-D 
Velocity 
The horizontal component of the velocity of the object remains unchanged 
throughout the motion. The vertical component of the velocity increases 
linearly, because the acceleration due to gravity is constant. The accelerations in 
the and directions can be integrated to solve for the components of velocity at 
any time , as follows: 
The magnitude of the velocity (under the Pythagorean theorem):
Derivation Of Projectile Motion in 2-D 
Displacement 
Displacement and coordinates of parabolic throwing 
At any time , the projectile's horizontal and vertical 
displacement: 
The magnitude of the displacement: Displacement and 
coordinates of parabolic 
throwing
Derivation Of Projectile Motion in 2-D 
Parabolic trajectory 
Consider the equations, 
If t is eliminated between these two equations the following equation is 
obtained: 
This equation is the equation of a parabola. Since , 
and are constants, the above equation is of the form 
in which a and b are constants. This is the equation of a parabola, so the path 
is parabolic. The axis of the parabola is vertical.
Derivation Of Projectile Motion in 2-D 
The maximum height of projectile 
The highest height which the object will reach is known 
as the peak of the object's motion. The increase of the 
height will last, until that is, 
Time to reach the maximum height: 
From the vertical displacement of the maximum height 
of projectile: 
Maximum height of projectile
Derivation Of Projectile Motion in 2-D 
The maximum distance of projectile 
It is important to note that the Range and the 
Maximum height of the Projectile does not depend 
upon mass of the trajected body. Hence Range and 
Maximum height are equal for all those bodies which 
are thrown by same velocity and direction. Air 
resistance does not affect displacement of projectile. 
The horizontal range d of the projectile is the horizontal 
distance the projectile has travelled when it returns to 
its initial height (y = 0). 
Maximum distance of 
projectile
Derivation Of Projectile Motion in 2-D 
Time to reach ground: 
From the horizontal displacement the maximum 
distance of projectile: 
So 
Note that d has its maximum value when 
which necessarily corresponds to 
Maximum distance of 
projectile
Factors Affecting Projectile 
Motion 
What two factors would affect projectile 
motion? 
– Angle 
– Initial velocity 
Initial Velocity 
Angle
Thank You!

Physics projectile motion

  • 1.
  • 2.
    Content Definition ofProjectile Definition of Projectile Motion Types of Projectile Motion Examples of Projectile motion Derivation of projectile motion in 2-D Factors Affecting Projectile Motion
  • 3.
    Definition Of Projectile A projectile is any object that once projected or dropped continues in motion by its own inertia and is influenced only by the downward force of gravity. By definition, a projectile has a single force that acts upon it - the force of gravity. If there were any other force acting upon an object, then that object would not be a projectile. Thus, the free-body diagram of a projectile would show a single force acting downwards and labeled force of gravity (or simply Fgrav). Regardless of whether a projectile is moving downwards, upwards, upwards and rightwards, or downwards and leftwards, the free-body diagram of the projectile is still as depicted in the diagram at the right. Fgrav Free-body diagram of a projectile
  • 4.
    Definition Of Projectile Motion Projectile motion is a form of motion in which an object or particle (called a projectile) is thrown near the earth's surface, and it moves along a curved path under the action of gravity only. Example: Parabolic water trajectory
  • 5.
    Types Of ProjectileMotion • 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
  • 6.
    Examples Of ProjectileMotion Launching a Cannon ball
  • 7.
    Examples Of ProjectileMotion Object thrown upward from a car moving in a horizontal direction
  • 8.
    Derivation Of ProjectileMotion in 2-D The initial velocity If the projectile is launched with an initial velocity , then it can be written as The components and can be found if the angle, is known: If the projectile's range, launch angle, and drop height are known, launch velocity can be found using Newton's formula The launch angle is usually expressed by the symbol theta, but often the symbol alpha is used. Initial velocity of parabolic throwing Components of initial velocity of parabolic throwing
  • 9.
    Derivation Of ProjectileMotion in 2-D Kinematic quantities of projectile motion In projectile motion, the horizontal motion and the vertical motion are independent of each other; that is, neither motion affects the other. Acceleration Since there is no acceleration in the horizontal direction, the velocity in the horizontal direction is constant, being equal to The vertical motion of the projectile is the motion of a particle during its free fall. Here the acceleration is constant, being equal to The components of the acceleration are:
  • 10.
    Derivation Of ProjectileMotion in 2-D Velocity The horizontal component of the velocity of the object remains unchanged throughout the motion. The vertical component of the velocity increases linearly, because the acceleration due to gravity is constant. The accelerations in the and directions can be integrated to solve for the components of velocity at any time , as follows: The magnitude of the velocity (under the Pythagorean theorem):
  • 11.
    Derivation Of ProjectileMotion in 2-D Displacement Displacement and coordinates of parabolic throwing At any time , the projectile's horizontal and vertical displacement: The magnitude of the displacement: Displacement and coordinates of parabolic throwing
  • 12.
    Derivation Of ProjectileMotion in 2-D Parabolic trajectory Consider the equations, If t is eliminated between these two equations the following equation is obtained: This equation is the equation of a parabola. Since , and are constants, the above equation is of the form in which a and b are constants. This is the equation of a parabola, so the path is parabolic. The axis of the parabola is vertical.
  • 13.
    Derivation Of ProjectileMotion in 2-D The maximum height of projectile The highest height which the object will reach is known as the peak of the object's motion. The increase of the height will last, until that is, Time to reach the maximum height: From the vertical displacement of the maximum height of projectile: Maximum height of projectile
  • 14.
    Derivation Of ProjectileMotion in 2-D The maximum distance of projectile It is important to note that the Range and the Maximum height of the Projectile does not depend upon mass of the trajected body. Hence Range and Maximum height are equal for all those bodies which are thrown by same velocity and direction. Air resistance does not affect displacement of projectile. The horizontal range d of the projectile is the horizontal distance the projectile has travelled when it returns to its initial height (y = 0). Maximum distance of projectile
  • 15.
    Derivation Of ProjectileMotion in 2-D Time to reach ground: From the horizontal displacement the maximum distance of projectile: So Note that d has its maximum value when which necessarily corresponds to Maximum distance of projectile
  • 16.
    Factors Affecting Projectile Motion What two factors would affect projectile motion? – Angle – Initial velocity Initial Velocity Angle
  • 17.