What Is The Law Of Inertia In Physics

Principle #: Law Of Inertia

The Law of InertiaInertia is the resistance of any physical object to any changes like starting or stopping a motion or changing direction… More says that a character will move with constant velocity unless acted on by an unbalanced force. First, lets be clear whats meant by an unbalanced force. The simplest form of the Law of InertiaInertia is the resistance of any physical object to any changes like starting or stopping a motion or changing direction… More is when there are no forces at all . In that case the object moves with constant velocity .

Heres a more down-to-earth example: A rock sitting on a table has two forces on it: gravity pulling downward and the tables surface pushing upward these two forces balance each other. A bowling ball rolling on a smooth floor has a similar pair of balanced forces and, again, these two forces balance. Since the forces are balanced the bowling ball rolls with constant velocity. If theres friction on the bowling ball then thats an unbalanced force and so the velocity wont be constant .

https://www.animatorisland.com/wp-content/uploads/2011/10/AlejandroGarcia.png Professor Alejandro Garcia has taught Physics of Animation at San Jose State since 2009. In 2011 he spent a one-year professional leave as physicist-in-residence at Dreamworks Animation SKG.

Find out more about Animation Physics on his website Animationphysics.org or his YouTube Channel

Inertia Of Rest Examples

Now that you know what inertia of rest is, explore several examples.

• If pulled quickly, a tablecloth can be removed from underneath the dishes. The dishes have the tendency to remain still as long as the friction from the movement of the tablecloth is not too great.
• If a stopped car is hit by a moving car from behind, the passengers inside may experience whiplash as a result of the body moving forward but the head lagging behind. The head is experiencing inertia.
• A balloon in a car will appear to move when the car moves forward, but the balloon is actually attempting to stay in the place it was, it is only the car that is moving.
• When a car is abruptly accelerated, drivers and passengers may feel as though their bodies are moving backward. In reality, inertia is making the body want to stay in place as the car moves forward.
• If an index card is placed on top of a glass with a penny on top of it, the index card can be quickly removed while the penny falls straight into the glass, as the penny is demonstrating inertia.
• When pulling a Band-Aid off, it is better to pull it fast. Your skin will remain at rest due to inertia, and the force pulls the Band-Aid off.

The Concept Of Inertia

The concept of inertia is a fundamental concept in physics. It is bounded with other fundamental concepts as:

The concept of state: the state of the system can be mechanical , thermodynamic, electromagnetic, etc. The state of a system is defined by the state parameters.

The concept of interaction.

The concept of process : Depending on the nature of the system,. The process consists in the transition of a system from a state to another. Given the causality principle, the process is the effect of interaction.

Depending on the nature of the systems and the nature of the states implied there are many types of processes: mechanical , electromagnetic, gravitational, chemical, thermodynamic etc.

Visit Our Virtual labsand Experience a Virtual World of Science Education

You May Like: Example Of Theorem In Geometry

Galileo And The Inertia Concept

The concept of inertia was created by Galileo, a leading scientist in the seventeenth century. According to Galileo, moving objects eventually come to a standstill due to a force known as friction. Galileo found that a ball would roll down one plane and up the opposite plane to roughly the same height in tests utilising a pair of inclined planes facing each other. The ball would roll up the opposite plane even closer to the original height if smoother planes were utilised. Any difference between the initial and final heights, Galileo reasoned, was attributable to friction. Galileo claimed that if friction were fully removed, the ball would soar to the exact same height.

Relation To Other Formulations Of Classical Physics

Classical mechanics can be mathematically formulated in multiple different ways, other than the “Newtonian” description . The physical content of these different formulations is the same as the Newtonian, but they provide different insights and facilitate different types of calculations. For example, Lagrangian mechanics helps make apparent the connection between symmetries and conservation laws, and it is useful when calculating the motion of constrained bodies, like a mass restricted to move along a curving track or on the surface of a sphere.:48Hamiltonian mechanics is convenient for statistical physics,:57 leads to further insight about symmetry,:251 and can be developed into sophisticated techniques for perturbation theory.:284 Due to the breadth of these topics, the discussion here will be confined to concise treatments of how they reformulate Newton’s laws of motion.

Recommended Reading: How Is Nuclear Power Physics

Newton’s First Law In Action

Rockets traveling through space encompass all three of Newton’s laws of motion.

Before a rocket is even launched, it is at rest on the surface of Earth. It would stay at rest indefinitely without any external force acting upon it. Newton’s first law also applies when the rocket is gliding through space with no external forces on it, it will travel in a straight line at a constant speed forever.

Now that we know how an object behaves when there is no outside force acting upon it, what happens when there is an outside force, such as the engines firing up in order to launch the rocket into space? That situation is described by Newtons Second Law of Motion.

Additional reporting by Rachel Ross, Live Science contributor.

See also:

Newtons Third Law: Action & Reaction

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

His third law states that for every action in nature there is an equal and opposite reaction. If object A exerts a force on object B, object B also exerts an equal and opposite force on object A. In other words, forces result from interactions.

Don’t Miss: What Is The Definition Of Element In Chemistry

Faqs On Inertial Force

1. What are the types of inertia?

There are three types of inertia the inertia of rest, the inertia of direction and the inertia of motion.

• Inertia of rest – It is the inability of a body to change its state by itself.

• Inertia of direction – The body cannot change its direction of movement by itself.

• Inertia of motion –It is the inability of an object to change its state of uniform motion by itself.

2. Give examples of the law of inertia.

Question: Describe The Types Of Inertia

Answer:

The following are three types of inertia

1. Inertia of Rest: When resistance is provided by the body to remain in a state of rest unless the external force is working through it.

2. Inertia of Direction: When resistance is provided by the body to continue to move in the same direction without the external force acting on it.

3. Inertia of Motion: When resistance is provided by the body to continue to be in the same direction without the external force acting on it.

Recommended Reading: What I Ve Learned In Math Essay

Galileo’s Experiments On The Motion Of Objects

Galileo was the first to argue that objects move at a constant speed when no external force acts on them. On the basis of doing a few simple experiments, he came to this revolutionary conclusion. Let us discuss his experiments where he studied motion of objects on an inclined plane. Galileo’s Experiment with single inclined plane:-Galileo first investigated the motion of objects on an inclined plane, as seen in the image below.

His Observations:-

Galileo’s Experiments on two inclined planes combined together:Galileo did another experiment using a double inclined planes facing each other as shown below in the figure

His Observations:-

Newtons Second Law: Force

The acceleration of an object depends on the mass of the object and the amount of force applied.

His second law defines a force to be equal to change in momentum per change in time. Momentum is defined to be the mass m of an object times its velocity V.

Let us assume that we have an airplane at a point 0 defined by its location X0 and time t0. The airplane has a mass m0 and travels at velocity V0. An external force F to the airplane shown above moves it to point 1. The airplanes new location is X1 and time t1.

The mass and velocity of the airplane change during the flight to values m1 and V1. Newtons second law can help us determine the new values of V1 and m1, if we know how big the force F is. Let us just take the difference between the conditions at point 1 and the conditions at point 0.

You May Like: What Is Suggestibility In Psychology

Newton’s Third Law Of Productivity 4

Third Law of Motion: When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

We all have an average speed that we tend to perform at in life. Your typical levels of productivity and efficiency are often a balance of the productive and unproductive forces in your life a lot like Newton’s equal and opposite forces.

There are productive forces in our lives like focus, positivity, and motivation. There are also unproductive forces like stress, lack of sleep, and trying to juggle too many tasks at once.

If we want to become more effective and more productive, then we have two choices.

The first option is to add more productive force. This is the power through it option. We gut it out, drink another cup of coffee, and work harder. This is why people take drugs that help them focus or watch a motivational video to pump themselves up. It’s all an effort to increase your productive force and overpower the unproductive forces we face.

Obviously, you can only do this for so long before you burn out, but for a brief moment the power through it strategy can work well.

The second option is to eliminate the opposing forces. Simplify your life, learn how to say no, change your environment, reduce the number of responsibilities that you take on, and otherwise eliminate the forces that are holding you back.

Physics In Animation: The Law Of Inertia

Get ready to be swept off your feet because today were talking inertiaInertia is the resistance of any physical object to any changes like starting or stopping a motion or changing direction… More! Yep, thats the physical principle that might literally sweep you off your feet during a bus ride and tosses you around in a roller coaster seat. Now, prepare to find out why it is important for your animation! Professor Alejandro Garcia, who teaches the course Physics of Animation at San José State, has returned to tell us about this law of nature that constantly influences you, me, or even a bowl of noodle soup whether still or in motion.

In Part 1 of this series I explained how knowing a little physics will help you observe motion in the real world and, if you want to, create animated motion thats believable. The principles youll learn apply to everything from a simple ball bounce to doing a complicated shot, such as a fight scene.

As mentioned in Part 1, here is my list of the Principles of Animation Physics:

• Action-Reaction

The first principle, Timing, SpacingSpacing is the distance an element travels between two frames of an animation. By increasing and decreasing the spacings… More, and Scale, was covered in Part 1 in this posting youll learn the Law of InertiaInertia is the resistance of any physical object to any changes like starting or stopping a motion or changing direction… More, also known as Newtons First Law of Motion.

Don’t Miss: What Do You Learn In Ap Physics

Early Understanding Of Inertial Motion

John H. Lienhard points out the Mozi based on a Chinese text from the Warring States period as having given the first description of inertia. Before the European Renaissance, the prevailing theory of motion in western philosophy was that of Aristotle . On the surface of the Earth, the inertia property of physical objects is often masked by gravity and the effects of friction and air resistance, both of which tend to decrease the speed of moving objects . This misled the philosopher Aristotle to believe that objects would move only as long as force was applied to them. Aristotle said that all moving objects eventually come to rest unless an external power continued to move them. Aristotle explained the continued motion of projectiles, after being separated from their projector, as an action of the surrounding medium continuing to move the projectile.

In the 11th century, Persian polymathIbn Sina claimed that a projectile in a vacuum would not stop unless acted upon.

What Are Newtons Laws Of Motion

Newtons laws of motion relate an objects motion to the forces acting on it. In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction.

Recommended Reading: What Is Positive Thinking In Psychology

A Detailed Discussion Of The Law Of Inertia

Newton’s first law of motion is also cited as the law of inertia.

This law states that a body continues to be in the state of rest or uniform motion along a straight line unless it is acted upon by an external force to change its state.

In our daily life, we find that a ball rolling on the ground stops after some time. This is because the frictional force of the ground is acting upon the ball to make changes in its state of motion.

The inertia of a body is measured by the mass of the body.

Heavier is the mass, greater is the force required hence, greater is its inertia and vice-versa.

Hence, Newtons first law defines inertia, and it is justly called the law of inertia.

Roller Coaster Project Report

INTRODUCTION The goal of this group project was to design and build an original paper model marble roller coaster that must be able to transport a marble from start to finish without interruptions. The design had to be unique and thrilling but safe and the marble must come to a complete stop at the end of the roller coaster. The track should have the following components: at least two hills, one loop and one turn, and if possible a jump.

Don’t Miss: Punchline Bridge To Algebra Why Was The Pail Pale Answers

Newton’s Laws Of Productivity

Newton’s laws of motion reveal insights that tell you pretty much everything you need to know about how to be productive.

Examples Of Inertia Of Rest In Our Daily Life

Now we will show some examples of law of inertia

• If an index card is placed on top of a glass with a penny on top of it, the index card can be quickly removed while the penny falls straight into the glass, as The cardboard moves away due to the force applied by the finger but the coin remains at its position due to inertia of rest and hence falls into the glass.

• When a bus or a train starts suddenly, the passenger standing inside it falls backward: It happens because the feet of the passenger being in contact with the floor of the bus come in motion along with the bus but the upper part of the body remains at rest due to inertia of rest. Hence the passenger falls backward.

• When a tree is vigorously shaken, some of the leaves fall from the tree: When the branch of a tree is vigorously shaken, the branch comes in motion as the force is applied on the branch. But the leaves want to remain at rest due to inertia of rest and fall down.

• The carpet is beaten with a stick to remove the dust particles: When carpet is beaten with stick, the carpet comes in motion but the dust particles remain at rest due to inertia of rest.

• A pile of a carom coins remains intact when the lowest coin in the pile is struck quickly by a striker.

Don’t Miss: What Is Replacement Rate In Geography