Newtons laws of motion examples

There was this fellow in England named Sir Isaac Newton. A little bit stuffy, bad hair, but quite an intelligent guy. He worked on developing calculus and physics at the same time. During his work, he came up with the three basic ideas that are applied to the physics of most motion (NOT modern physics). The ideas have been tested and verified so many times over the years, that scientists now call them Newton's Three Laws of Motion.

First Law

The first law says that an object at rest tends to stay at rest, and an object in motion tends to stay in motion, with the same direction and speed. Motion (or lack of motion) cannot change without an unbalanced force acting. If nothing is happening to you, and nothing does happen, you will never go anywhere. If you're going in a specific direction, unless something happens to you, you will always go in that direction. Forever.

You can see good examples of this idea when you see video footage of astronauts. Have you ever noticed that their tools float? They can just place them in space and they stay in one place. There is no interfering force to cause this situation to change. The same is true when they throw objects for the camera. Those objects move in a straight line. If they threw something when doing a spacewalk, that object would continue moving in the same direction and with the same speed unless interfered with; for example, if a planet's gravity pulled on it (Note: This is a really really simple way of descibing a big idea. You will learn all the real details - and math - when you start taking more advanced classes in physics.).

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Examples of Newton’s First Law of Motion
1. Brakes applied by a Bus Driver Abruptly
2. An Object Placed on a Plane Surface
3. Marathoner Running beyond Finish Line
4. A Ball Rolling on the Ground
5. An Object Thrown in Outer Space
6. Washing Machine Dryer
7. Dusting a Carpet
8. Shaking a Tree
9. The Jerk when a Vehicle Starts
10. Athlete taking a Short Run before Long/High Jump

Second Law

The second law says that the acceleration of an object produced by a net (total) applied force is directly related to the magnitude of the force, the same direction as the force, and inversely related to the mass of the object (inverse is a value that is one over another number... the inverse of 2 is 1/2). The second law shows that if you exert the same force on two objects of different mass, you will get different accelerations (changes in motion). The effect (acceleration) on the smaller mass will be greater (more noticeable). The effect of a 10 newton force on a baseball would be much greater than that same force acting on a truck. The difference in effect (acceleration) is entirely due to the difference in their masses.

Third Law

The third law says that for every action (force) there is an equal and opposite reaction (force). Forces are found in pairs. Think about the time you sit in a chair. Your body exerts a force downward and that chair needs to exert an equal force upward or the chair will collapse. It's an issue of symmetry. Acting forces encounter other forces in the opposite direction. There's also the example of shooting a cannonball. When the cannonball is fired through the air (by the explosion), the cannon is pushed backward. The force pushing the ball out was equal to the force pushing the cannon back, but the effect on the cannon is less noticeable because it has a much larger mass. That example is similar to the kick when a gun fires a bullet forward.

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Newton's Laws Aboard The ISS (NASA-eClips Video)

Newton’s first law of motion states that an object continues to maintain its state of rest or motion unless or until it is acted upon by an external force. It is also known as the law of inertia. As per the statement of the first law of motion, two types of inertia exist in nature, namely, the inertia of rest and inertia of motion. Inertia is the natural tendency of a body to resist change in its state. It is proportional to the mass of the object, which means greater be the mass, greater is the inertia possessed by the body and vice-versa. The laws of motion were discovered in the year 1687 by an English mathematician, physicist, astronomer, theologian, and author, Sir Issac Newton. The laws of motion are mentioned in one of the books written by him called Philosophiae Naturalis Principia Mathematica, commonly known as the Principia. In simple words, the first law of motion states that an object at rest stays at rest and an object in motion continues to exhibit motion, provided no force acts on the object from the outside.

Examples of Newton’s First Law of Motion

1. Brakes applied by a Bus Driver Abruptly

While travelling on a bus, when the bus driver abruptly applies the breaks, we tend to feel a momentary pull in the forward direction. The reason behind this jerk felt by the passengers sitting inside the bus is the law of inertia. Due to the inertia of motion, our body continues to maintain a state of motion even after the bus stops, thereby pushing us in the forward direction.

2. An Object Placed on a Plane Surface

One of the finest examples of Newton’s first law of motion is an object that is simply placed on the surface of the earth. The natural tendency of the object is to maintain its state of rest until a force acts on it. For instance, a book kept on a bookshelf does not change its shape, size, or position until acted upon by an external force.

3. Marathoner Running beyond Finish Line

A marathon runner is not able to stop himself right after crossing the finish line. He/She tends to take time and cover a few meters of distance running beyond the finish line. This is because the inertia of motion or Newton’s first law of motion resists a sudden termination of motion and compels the body to maintain its state of motion.

4. A Ball Rolling on the Ground

As per Newton’s first law of motion, a ball rolling on the ground tends to maintain its state of motion till infinity, if no external force acts on it; however, the force of friction acting on the ball from the outside helps to break the motion of the ball and brings it to rest.

5. An Object Thrown in Outer Space

If an object is thrown in outer space, it tends to move in a direction to infinity. This is because outer space lacks environment, air, and the force of gravity. Hence, the object does not receive any resistance to the motion; therefore, it continues to exhibit motion until it hits a celestial body, strikes a meteorite, or enters the gravitational field of a planet, thereby demonstrating the first law of motion in real life.

6. Washing Machine Dryer

A washing machine dryer entirely works upon the principle of the law of inertia. To dry the clothes, the drum of the washing machine dryer is subjected to motion, which further causes the clothes to move; however, the water molecules contained in the cloth do not follow the motion and stay at their position of rest. Due to the gravitational pull of the earth, the water gets collected at the base of the drum. The holes of the drum let the water out, leaving the clothes dry.

7. Dusting a Carpet

To remove the dust particles from a carpet, it is hanged on a wire and a piece of the stick is used to hit the carpet repeatedly. This induces motion in the carpet, whereas the dust particles continue to maintain their state of rest. When the carpet moves back, the dust particles get carried away with air or fall to the ground due to gravity, thereby demonstrating the law of inertia.

8. Shaking a Tree

When the branch of a tree is vigorously shaken with the help of an external force, it comes to motion; however, the leaves attached to the branch do not comprehend the motion and tend to maintain their state of rest. The motion of the branch of the tree and the inertia of rest exhibited by the leaves cause the shedding of leaves.

9. The Jerk when a Vehicle Starts

When a vehicle starts suddenly, a jerk is felt by the passengers and the drivers sitting inside the vehicle that pulls them backwards. This is because the car comes in motion, but the body continues to sustain its state of rest, thereby leading to a sudden and momentary change in the state known as a jerk.

10. Athlete taking a Short Run before Long/High Jump

An athlete takes a short distance run before a long jump or a high jump. This is because by running a short distance, the player prepares his body and sustains motion in it. This helps him to exhibit a smooth jump. A similar demonstration of the inertia of motion can be observed when a bowler takes a small run before throwing a ball.