Inertia Facts: Amazing Things You Might Not Know

Abhijeet Modi
Nov 03, 2023 By Abhijeet Modi
Originally Published on Apr 05, 2022
Cartesian impulse conservation law experiment metallic balls
?
Age: 3-18
Read time: 7.4 Min

The law of inertia states that an object will keep doing whatever it is doing before a force acts upon it.

In the absence of a net force, an object will stay at rest or keep moving in a straight line at a constant speed. Inertia is related to mass and velocity, meaning that the greater the mass an object has or, the faster an object travels, the more inertia it has.

Inertia is affected by air resistance. The more air resistance an object has, the more inertia it has.

This means that heavier and faster objects have a stronger inertial force than lighter and slower objects. So the next time you are throwing a ball in the air, remember that it is your hand doing all the work.

Gravity is what makes an object fall towards Earth and not fly off into space. If you hold onto something heavy or push yourself away from something, then inertia will make you continue to do so.

Different Types Of Inertia

Inertia, which is also known as Newton's first law, is the force that is applied by the body or an object. It shows its resistance while in motion on its axis.

There are three different types of inertia: the inertia of rest, the inertia of motion, and the inertia of direction. When an object or body is not able to move on its own, and the object stays in its stable position, this is known as the inertia of rest.

For example, when you are driving the car and the car stops at the red light.

At this point in time, your body is at rest. When it's a green light and the car starts, it gives a jerk, and your body resists the motion. The body wants to remain at rest.

This is known as the inertia of rest. The second is the inertia of motion. When the body is not able to change its position from motion, this is known as the inertia of motion.

For example, if a train comes to a sudden halt, we are forced to fall in the forwarding direction. The top portion of the body is in contact with the seat as a result of inertia, while the rear of the train moves forward, making the lower half, on the other hand, strive to stay stationary.

The third is the inertia of direction.

The object's inability to make a change in the direction of its motion is known as the inertia of direction. For example, when you are driving a bike, the body will not be able to make a change in direction until the body does not want to change the direction.

The bike will make a turn in its direction only when allowed by the body.

Examples To Understand Inertia

A ball tossed into the air rises to its maximum height before crashing to the ground.

A feather falls slower than a rock because it has less inertia; it is less resistant to change. When you throw a ball, your hand provides the force, and the ball starts moving due to the force provided by your hand.

The ball keeps traveling at a steady speed until it reaches its highest point and then begins to fall toward the ground.

When you throw a feather, your hand provides the force, and the feather starts moving due to the force provided by your hand. Unlike a ball, however, the feather decreases its speed as it rises towards its highest point because of air resistance. The greater the distance between an object and the ground, the more air friction it encounters.

Thus, as an object moves away from a planet, Earth's gravitational pull decreases, and, hence, there is a decrease in inertia. When objects are not subject to any other force, they move at a constant speed in a straight line.

This is why objects on the surface of the Earth that are not moving usually stay still. Tornadoes and hurricanes, on the other hand, are outliers to this norm.

Toy gyroscope spinning and balancing on a wooden table

Scientific Facts About Inertia

As an object's speed is increased, so does the rotational inertia.

This is one reason why spinning objects are more difficult to stop than non-spinning objects, which can be explained by Newton's first law of motion, otherwise known as the law of inertia. Rotational inertia also explains why an object's rate of rotation changes when it alters its mass or radius.

The speed of an object's rotation is also affected by air resistance. An object will encounter extremely minimal friction if there is very little air resistance, and its rotational inertia would stay unchanged. However, when air resistance is present, it will cause the rotational inertia to decrease.

When objects are spun in space where there is no gravity or atmosphere, the rotational inertia remains intact as long as no other forces are exerted upon them. Inertia is a property of matter, referring to its resistance to any change in its state of motion.

This then refers to the tendency of an object that is stationary or moving in a straight line to remain in motion unless outside forces are applied. The earliest known person to describe inertia was Galileo Galilei, and it was later expanded by René Descartes. This law means that if something is moving, it will keep moving.

If an object is stationary, it will remain so unless an outside force acts upon it.

Inertia came to be described by Newton as a law of motion in the 17th century; 'Every body persists in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by force impressed.'

FAQs

Is inertia a force?

Yes, inertia is a force applied by an object in a particular direction. According to Newton's laws, inertia and mass are similar or proportional to each other. If an object stays at rest, its mass and inertia will also remain the same, and if the object is moving at a great speed, its inertia and mass will eventually increase.

What is the moment of inertia?

The moment of inertia is somewhat similar to rotational inertia. When an object moves in a straight line in the same direction, the resistance it shows while rotating is called the moment of inertia.

How to find a moment of inertia?

To calculate the moment of inertia of an object, add up all of its pieces or parts and then multiply them by the square of the distance they covered to its axis. The equation for the moment of inertia is I = r2dm.

Which object has the greatest inertia?

It isn't limited to a single object. The more mass an object or body has, the more inertia the object has. The greatest inertia of an object is totally dependent on its mass and motion.

What is sleep inertia?

When you wake up and still feel sleepy with feelings of tiredness, drowsiness, grogginess, and an absent mind, it is defined as sleep inertia. This is commonly observed when the person's sleep is not complete, and they want to sleep again.

What is the law of inertia?

Newton's first law, or the law of inertia, means when an object stays at rest, it will be at rest. But when the object or body moves, it will move at the same speed in the same direction in a straight line until it is interrupted by any external force. This is called the law of inertia.

What is rotational inertia?

When an object or body rotates in the right or left direction, it shows some resistance while rotating. The object's resistance at an angular velocity and angular momentum is called rotational inertia.

What is inertia measured in?

A kilogram is used to measure inertia, and the short form of the SI Unit is kg m2. The mass of the inertia helps to measure the external force action, while the moment of inertia helps to measure the axis of the object.

How is mass related to inertia?

Mass and inertia are interrelated with each other. The more inertia a body or object has, the more the object or body has mass. They move at constant speed in the same direction and at the same speed.

What is inertia in a person?

Inertia in a person means that when any linear motion is made by the human body, the net force applied increases. Similarly, when the body stays at rest, no external force is applied.

When it comes to the concept of psychology, then if some tragic incident happens to someone, the person's resistance is visible in comparison to when the person is more confident.

This constant speed difference in the thought process along with the body is called inertia in a person. For example, seat belts help the body to meet any tragic incident, and a person uses the front brakes of the car by maintaining the speed of the car in a more confident way.

We Want Your Photos!
We Want Your Photos!

We Want Your Photos!

Do you have a photo you are happy to share that would improve this article?
Email your photos

More for You

Sources

https://studiousguy.com/inertia-examples/

https://blog.praxilabs.com/2021/12/19/examples-of-law-of-inertia/

https://examples.yourdictionary.com/examples-of-inertia.html

https://sciencing.com/inertia-what-is-it-why-is-it-important-wexamples-13720235.html

https://www.physicsclassroom.com/class/newtlaws/Lesson-1/Inertia-and-Mass

See All

Written by Abhijeet Modi

Master of Computer Science

Abhijeet Modi picture

Abhijeet ModiMaster of Computer Science

An experienced and innovative entrepreneur and creative writer, Abhijeet holds a Bachelor's and Master's degree in Computer Application from Birla Institute of Technology, Jaipur. He co-founded an e-commerce website while developing his skills in content writing, making him an expert in creating blog posts, website content, product descriptions, landing pages, and editing articles. Passionate about pushing his limits, Abhijeet brings both technical expertise and creative flair to his work.

Read full bio >