Force and Inertia

Inertia

Sir Isaac Newton’s contributions to physics are unparalleled. In classical physics, his laws of motion altered everything. The first of his three laws of motion deals with inertia. So let’s begin by defining inertia. 

The Latin word ‘iners,’ which means lethargic or idle, is the root of the English word ‘inertia.’ Kepler was the first to use the word. Inertia is a property of all concern with the mass present in all things. Until a force alters its speed or direction, an object formed of matter continues in its current state. For instance, without some force, a ball cannot begin to roll independently. Moreover, unless gravity or collision is present, a ball tossed into a frictionless space will continue to move in the same direction and speed for eternity.

Inertia is measured in terms of mass. The larger the mass of an object, the more difficult it is to change its motion or rest. For example, when moving a car, you’ll need to exert a greater amount of force. On the other hand, pedalling a bicycle will necessitate a lower level of aggressiveness. The car’s mass is more than the bike’s, which accounts for the discrepancy in force. The inertia of a car is more than the inertia of a bike.

Inertia: Definition

As previously stated, the property of objects by which it cannot change its state of rest across a straight line unless it is subjected to an external force can be defined as inertia. The body’s inertia rises as the body’s mass grows, and the converse is true. Because of inertia, when we suddenly apply the brakes to a moving vehicle, we feel a jerk in our body.

The Inertia Principle

Based on Galileo’s work, Sir Isaac Newton developed his first law of motion. He discovered that a ball rolling in a certain way takes a certain amount of effort to stop it once it has started moving in that direction. For the ball’s velocity and direction to alter, force must be applied. Newton’s definition of the Law of Inertia:

Newton writes in his Principia Mathematica that, “The velocity of bodies included in a given space is equal among themselves, whether that space is at rest or flows evenly forward in a straight line without circular motion”. If an object does not receive external force, it will be either at rest or moving. Newton’s Second Law of Motion derives the relationship among acceleration, force, and mass.

Newton’s Third Law of Motion defines that when a force is applied to one object, another equal force is used to the origin of the force. According to this law, every action has an equal and opposing reaction. For example, when someone pulls on a rope, it pulls back the one doing the pulling.

Force

A force is defined as the push or pull an object exerts on another. When two items come into contact with each other, they both exert a force on each other. Stretch and squeeze are other words that can be used to describe forces. What does it mean to have “force” in physics?

“Push or pull that alters the velocity at which anything with mass travels.”

Force is an external factor that can alter a specific body’s condition of rest or motion. It has both a magnitude and a direction of travel. The applied force is called force direction, and the spot where force is used is called force location.

You can find out how much force is at work by utilising a spring balance. Newton (N) is the SI unit of force.

Force’s Effects

A change in location over time is called motion in physics. Generally speaking, motion can be described as either:

• Changes in the rate of movement
• Change in direction 

Here are a few examples of how the force can have various impacts.

1. Force is capable of causing a body to move while it is at rest.
2. It can either halt or slow down a moving object.
3. It can increase the speed of an object in motion.
4. Additionally, it can alter the shape and size of a moving object.

Force Formula

It is possible to express the equation or the formula of force mathematically in the following way:

F = ma 

In this case,

m denotes mass, and a denotes acceleration.

It is expressed in Newtons (N) or kilogram meter per second square (Kg m/s2).

The formula for acceleration 

a=vtis a mathematical expression.

Where,

Δv is the change in velocity

Δt is the amount of time it took.

As a result, a force can be expressed as follows:

F=mvΔt is the formula for finding the value of F.

The inertia formula is denoted by the symbol p = mv, which can also be expressed as momentum.

Because of this, the force can be defined as the rate at which momentum changes over time.

F=pt

In any given problem, force formulae can help determine the amount of force, mass, acceleration, momentum, and velocity present.

Different Kinds of Force

Force is a physical cause that can alter an object’s state of motion or dimensions. Based on their applications, forces are classified into two types:

1. Contact force
2. Non-contact force

The following are some examples of contact forces:

• Muscular force
• Normal force
• Frictional force

Non-contact forces work across spaces without making direct touch with the body.

Non-contact forces include the following:

• The force of gravity
• Force of electrostatic attraction
• The magnetic force

Magnetic force is the force produced by a magnet on other magnets. Because magnetic and electrostatic forces act on an object from a distance, they are non-contact forces. On the other hand, gravity is an attracting force applied by the Earth on bodies, causing them to fall to the ground. 

Summary

The body’s inertia rises as the body’s mass grows, and the converse is true. A force is defined as an object being pushed or pulled. When two items come into contact with each other, they exert a force on each other. Stretch and squeeze are other words that can be used to describe forces. Force is a physical cause that can alter an object’s state of motion or dimensions. Based on their applications, forces are classified into two types: Contact Forces and Non-Contact Forces.