Projectile Motion | What projectiles | Law of Inertia

A projectile is any object that is propelled into the air or space and continues in motion due to its own inertia, influenced only by the force of gravity and, in some cases, air resistance. Common examples include a ball thrown into the air, a bullet fired from a gun, or a stone released from a slingshot.

What is Law of Inertia

Inertia is a fundamental concept in physics, referring to the property of matter that resists changes in its state of motion. An object will remain at rest or continue moving with constant velocity unless acted upon by an external force. This principle is encapsulated in Newton’s First Law of Motion, often called the Law of Inertia.

Key Points:

• At Rest: An object at rest will stay at rest unless a force causes it to move.

• In Motion: An object in motion will continue moving with constant velocity in a straight line unless a force changes its speed or direction.

Inertia is directly related to an object’s mass; the greater the mass, the greater its inertia, making it more resistant to changes in motion.

Examples:

• At Rest: A book lying on a table remains stationary until someone applies a force to move it.

• In Motion: A car traveling at a constant speed on a highway will continue at that speed unless forces like friction, air resistance, or braking act upon it.

The study of projectiles falls under the topic of projectile motion, which examines the motion of these objects under the influence of gravity. Projectile motion is characterized by a curved trajectory, typically a parabola, resulting from the combination of an initial horizontal velocity and the downward acceleration due to gravity.

What is Projectile Motion

Projectile motion refers to the motion of an object that is projected into the air and moves under the influence of gravity alone, following a curved path known as its trajectory. This motion is characterized by two independent components: horizontal motion with constant velocity and vertical motion under constant acceleration due to gravity.

Key aspects of projectile motion include:

• Horizontal Motion: The horizontal component of velocity remains constant throughout the flight, as there are no horizontal forces acting on the projectile (assuming air resistance is negligible).

• Vertical Motion: The vertical component of velocity changes due to the constant acceleration of gravity, which acts downward at approximately 9.8 m/s².

The combination of these motions results in a parabolic trajectory. Understanding the principles of projectile motion is essential for analyzing the behavior of objects in various scenarios, from sports to engineering applications.