Projectile Motion

A body thrown with some initial velocity in a direction making an angle with the horizontal direction and then allowed to move under the action of gravity alone, is known as a Projectile.

Projectile moves in a path which is considered as a part of parabola .Such motion is called projectile motion.

A body can be projected in two ways:

• It can be projected horizontally from a certain height.
• It can be thrown from ground in a direction inclined to it.

Projectile possesses two motions simultaneously:

• It possesses a horizontal motion with a constant velocity.

• It possesses a vertical motion downwards with a constant acceleration.

Hence the projectile undergoes a vertical motion as well as horizontal motion. The two components of projectile motion are

• Vertical component
• Horizontal component

These two components are independent of each other.

A body projected with initial velocity making an angle with horizontal direction possess uniform horizontal velocity and variable vertical velocity, due to force of gravity. The object therefore has horizontal and vertical motion simultaneously.

The resultant would be the vector sum of these two motions and the path followed would be curvilinear.

In a given time interval, vertical distance travelled by an object thrown parallel to the surface of earth is same as that travelled by an object dropped directly from the same height. Hence vertical motion of the projectile is independent of its horizontal motion.

The horizontal distance travelled by a projectile depends on the speed with which it is thrown horizontally. Larger the initial speed with which a projectile is thrown horizontally, greater will be the horizontal distance travelled by it.

Angle of projection:

The angle between the initial direction of projection and the horizontal direction through the point of projection is called the angle of projection.

Velocity of Projection:

The velocity with which the body is projected is known as velocity of projection.

Range:

Range of projectile is the horizontal distance between the point of projection and the point where the projectile hits the ground.

Trajectory:

The path described by the projectile is called the trajectory.

Time of flight:

Time of flight is the total time taken by the

projectile from the instance of projection till it strikes the ground.