Horizontal Projectile Motion-Class 11 Physics Notes

Projectile Motion

When a particle is projected obliquely near the earth’s surface, it moves in horizontal as well as vertical directions simultaneously. The motion of such a particle is known as the projectile motion.

Rectilinear motions involved in projectile motion are:

Two independent simultaneous motions are responsible for projectile motion.

1. X-axis: uniform velocity is accountable for the horizontal motion of the particle (forward movement).
2. Y-axis: uniform acceleration is accountable for the vertical motion of the particle (downward movement).

Projectile motion is categorised into:

• Horizontal motion
• Vertical motion

What Is Horizontal Motion?

Did you know the only force acting upon a projectile is gravity? Gravity proceeds to impact the vertical motion of the projectile generating a vertical acceleration.

A projectile’s horizontal motion is the result of the tendency of any object to persist the motion at a constant velocity. Since horizontal forces are absent, the projectile continues to be in motion at a constant horizontal velocity. Here, to keep a projectile moving horizontally, horizontal forces are not necessary. The horizontal motion of a projectile is independent of its vertical motion.

The motion of a projectile in a horizontal plane, which depends upon the force acting on it, is known as horizontal motion.

The horizontal component of the speed of a projectile is constant throughout the flight duration. Since after launching the projectile, no horizontal force acts on it. This is the reason the projectile travels horizontally at a constant speed. Let us know how to calculate the distance (x) covered by a projectile.

Distance = speed × Time

x = vt

Examples of Horizontal Motion

After learning the definition of horizontal motion, let us know some examples of horizontal motion.

• A boat travelling in a river.
• A bullet fired from a gun.
• Throwing a ball or a cannonball.
• Movement of a billiard ball on the billiard table.
• The motion of the planet Earth around the Sun.

Frequently Asked Questions – FAQs

Q1

What is horizontal motion?

The motion of a projectile in a horizontal plane, which depends upon the force acting on it, is known as horizontal motion.

Q2

What is the formula to calculate the distance covered by a projectile?

Distance = speed × Time
x = vt

Q3

What is the only force acting upon a projectile?

The only force acting upon a projectile is gravity.

Q4

State true or false: A bullet fired from a gun is an example of circular motion.

False. A bullet fired from a gun is an example of projectile motion.

Q5

How is projectile motion categorised?

Projectile motion is categorised into:

1. Horizontal motion
2. Vertical motion