# 7 Law Of Inertia Examples In Everyday Life | Physics

## Top 7 Law of Inertia Examples In Physics & Daily Life | Types of Inertia Examples

Here are the top 7 Law of inertia examples In Physics and real Life.

7. ### A coin thrown vertically upwards inside the train (Inertia Of Direction)

The law of inertia is often referred to as Newton’s first law of motion. This law is one of the foundational concepts in classical mechanics and was formulated by Sir Isaac Newton in the 17th century.

It states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. In this article, we will explore 7 different Law of inertia examples. We will cover all types of inertia examples such as inertia of rest, inertia of motion & inertia of direction.

But before you read any further, it might be a good idea to briefly understand what inertia is and its types. We will cover them very briefly. So it is recommended to read it, as it will help you to understand the examples better. If you are already familiar with the concept, you can skip it by clicking on the link below.

### What is the law of inertia in physics?

In physics, inertia is a fundamental property of matter that describes an object’s resistance to a change in its state of motion. It is one of the key principles underlying Sir Isaac Newton’s laws of motion. Inertia is often summarized by the statement:

“An object at rest tends to stay at rest, and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an external force.”

In simpler terms, if an object is stationary, it will remain stationary unless a force is applied to it. Similarly, if an object is moving, it will continue to move at a constant velocity in a straight line unless a force is applied to change its speed or direction.

### Types of inertia with examples

Inertia can be categorized into three main types:

1. Inertia of Rest: This refers to the tendency of an object to remain at rest when no external force is acting on it. In other words, an object at rest will stay at rest unless a force is applied to set it in motion.
Example: A book sitting on a table will not move on its own because it exhibits inertia of rest. It requires an external force, such as someone pushing it, to overcome this inertia and make it move.
2. Inertia of Motion: This describes the tendency of an object in motion to remain in motion with the same speed and in the same direction unless acted upon by an external force. It is sometimes referred to as “inertia of motion” or simply “inertia.”
Example: If you roll a ball on a smooth, frictionless surface, it will continue rolling indefinitely in a straight line unless an external force, such as friction or your hand, acts upon it to slow it down or change its direction.
3. Inertia of Direction: Inertia of direction is a concept related to an object’s tendency to resist changes in its direction of motion. This means that an object will continue moving in its current direction unless an external force is applied to change that direction.
Example: When you’re driving a car and suddenly make a sharp turn, you feel yourself being pushed to the side. This is because your body tends to continue moving in the direction it was initially going (inertia of motion), and the car’s rapid change in direction exerts a force on you (inertia of direction).

So let’s dive into our top 7 law of inertia examples in physics & daily life.

## I am certain that the concept of inertia of rest is clear to you now. If not, you can comment below. Let us now move on to our top 7 examples of the Law of inertia in physics & in real life.

1. Dust particles in a woolen blanket:

When you have a woolen blanket that has been lying undisturbed for some time, you may notice dust particles settled on it. These dust particles remain still on the surface of the blanket due to the concept of inertia of rest.

2. Roller In the Lawn:

A large force is required to set up a stationary lawn roller into motion. Once it is set up in motion, only a small force is needed to continue it in motion.

3. A Man Getting Down from a Moving Bus:

When a man attempts to get down from a moving bus, he experiences inertia of motion. This means that his body continues to move forward at the same speed as the bus due to its initial motion. As he steps off the bus, he suddenly finds himself in a state of relative rest, while the bus continues moving.

As a result, he might stumble or fall forward unless he actively applies a force, such as stepping with the same speed as the bus to match its motion, to counteract his forward momentum.

4. Athlete Runs Before Taking a Long Jump:

An athlete running before a long-jump is a classic example of inertia of motion. As the athlete sprints down the track, their body is in motion. When they take off for the jump, they rely on their forward motion to carry them through the air.

In the absence of this forward motion, they wouldn’t be able to cover the distance of the jump effectively. This showcases how an object in motion tends to remain in motion unless acted upon by an external force, allowing the athlete to execute the jump successfully.

5. A Passenger Sitting in a Moving Car Falls Forward When the Car Suddenly Stops:

This scenario demonstrates the inertia of motion in action. When a passenger is sitting in a moving car, both the passenger and the car are in motion. When the car suddenly stops, the passenger’s body still possesses the forward motion it had when the car was moving.

As a result, the passenger continues moving forward inside the car until an external force, like the car’s brakes or seatbelt, acts to stop them. This is why the passenger falls forward, following the principle that an object in motion tends to stay in motion unless acted upon by an external force.

6. Car Turning on a Curve

When a car turns on a curve, the passengers inside it initially tend to continue moving in the direction they were traveling before the turn due to the inertia of direction. This means that if the car turns to the right, the passengers’ bodies have a tendency to keep moving forward, which, relative to the car’s new direction, would be to the left.

As a result, when the car turns right, passengers often lean or feel as if they are pushed to the left inside the car. This sensation occurs because their bodies resist changing their forward motion and tend to continue moving in the direction the car was traveling before the turn, in accordance with the principle of inertia of direction.

However, once the car completes the turn and continues on its new path, the passengers adjust to the new direction of motion. So, after the turn, passengers do not continue moving in the opposite direction; they align themselves with the car’s new forward motion, demonstrating the role of inertia of direction in this experience.

7. A coin thrown vertically upwards inside the train (Three Cases)

Case 1: Train Moving with Uniform Velocity

In this scenario, when the train is moving with uniform velocity (constant speed and direction), the coin initially shares the train’s motion. When you throw the coin upward, it continues to move upward with the same velocity as the train, maintaining its initial direction.

This is because of the inertia of direction, as the coin resists changing its motion while inside the moving train. From an external perspective, someone outside the train would observe the coin moving vertically within the train car.

Case 2: Train Moving with Uniform Acceleration

When the train accelerates uniformly, the coin initially shares the train’s motion. When you throw the coin upward, it will continue to move upward relative to the train car due to the inertia of direction. However, inertia of direction also means that the coin resists changes in its horizontal motion.

So, from an external perspective (someone outside the train), they would observe the coin’s trajectory as not following a straight vertical path.

Instead, due to the train’s acceleration, the coin will appear to fall backward toward the person who threw it. This is because, while the coin is moving upward, the train itself has moved forward since the coin was released.

The coin’s initial forward velocity inside the moving train combines with the train’s acceleration to create a curved trajectory, causing it to fall backward, illustrating the role of inertia of direction.

Case 3: Train Retarding Uniformly

When the train is uniformly decelerating or slowing down, the coin initially moves with the train’s motion. When thrown upward, it will continue to move upward relative to the train car due to inertia of direction. However, inertia of direction means that the coin resists changes in its horizontal motion.

From an external perspective (someone outside the train), they would observe the coin’s trajectory as not following a straight vertical path. Due to the train’s deceleration, the coin will appear to fall forward, towards the front of the train.

This is because, while the coin is moving upward, the train has slowed down since the coin was released. The coin’s initial forward velocity inside the moving train combines with the train’s deceleration to create a curved trajectory, causing it to fall forward, demonstrating the role of inertia of direction.

### References – Law Of Inertia examples

• The Physics Classroom: Inertia

If you are interested in learning about inertia, it could be a valuable educational resource to explore. It is provided by the physics classroom.