Newtons Third Law

You’re probably aware of the Earth’s gravitational pull on you. You might not realize it, but you’re pulling up on the Earth as well. For example, if the Earth exerts a gravitational force of 500 N on you, you exert a gravitational force of 500 N on the Earth. This incredible phenomena is due to Newton’s third law.

Newton’s third law: law of action and reaction

When two bodies make contact, Newton’s third law states that forces of equal magnitude and opposite direction are applied to one another. The law of action and reaction is referred to as the third law. This law is useful in studying static equilibrium situations, in which all forces are balanced, but it also applies to bodies moving in a uniform or rapid motion. It’s not a tally system, but it does describe real-world forces. For example, a book on a table produces a downward force on the table proportional to its weight. The book is subjected to an equal and opposite force by the table, according to the third law. The table deforms and acts like a coiled spring, pressing back on the book due to the weight of the book.

A body subjected to a net force experiences accelerated motion according to the second law. If there is no net force acting on the body, either because there are no forces at all or because all forces are properly balanced by opposing forces, the body does not accelerate and is said to be in equilibrium.

 A body that is not accelerated, on the other hand, may be assumed to be devoid of net force.

Influence of Newton’s law

Newton’s laws were initially published in the Principia Mathematica, which was his magnum opus (1687). Nicolaus Copernicus proposed in 1543 that the Sun, not the Earth, was the center of the universe. In the years that followed, Galileo, Johannes Kepler, and Descartes lay the groundwork for a new science that would both replace and explain the workings of the Aristotelian worldview. That new science was born in Newton’s Principia. He developed his three principles to explain why the planets’ orbits are ellipses rather than circles, which he succeeded in doing, but it turned out that he explained a lot more. The Scientific Revolution refers to the events that occurred from Copernicus to Newton as a whole. Quantum mechanics and relativity supplanted Newton’s principles as the most fundamental laws of physics in the twentieth century. Despite this, Newton’s laws continue to accurately describe nature, with the exception of very small entities such as electrons or bodies flying at near-light speeds. For larger bodies or slower moving bodies, quantum mechanics and relativity reduce to Newton’s rules.

Examples of Newton’s third law

• Other applications of Newton’s third law are plentiful. As she strides in front of a whiteboard, a lecturer pushes herself backwards on the floor. The professor experiences a forward reaction force from the floor, causing her to speed forward.
• A car accelerates in the same way because the ground pushes forward on the drive wheels in response to the drive wheels pushing backward on the ground. When tires spin on a gravel road and send boulders backward, you may see evidence of the wheels pushing backward.
• Rockets, for example, propel themselves forward by ejecting high-velocity gas backwards. This means that the rocket applies a significant backward force to the gas in the rocket combustion chamber, and the gas, in turn, applies a large forward reaction force to the rocket. This reactive force is known as thrust. Rockets are frequently mistaken to propel themselves by pushing against the earth or air. Because the exhaust gasses can be discharged more easily in a vacuum, they function better. Helicopters create lift in a similar way by pushing air down and feeling an upward response force.
• Take a look at the way birds fly. A bird uses its wings to fly. A bird’s wings push air downwards. Because forces are generated by mutual interactions, the air must be pulling the bird higher as well. The force on the air is equal to the force on the bird, and the force on the air (downwards) is opposite the force on the bird (upwards). There is an equal (in size) and opposite (in direction) reaction to every action. So, Birds  fly because of action-reaction force couples.

CONCLUSION

A force is a push or a pull that occurs as a result of one object’s interaction with another object. Interactions result in forces! Contact interactions produce some forces (normal, frictional, tensional, and applied forces are examples of contact forces), while action-at-a-distance interactions produce other forces (gravitational, electrical, and magnetic forces). When you sit on your chair, your body produces a downward force on the chair, and the chair exerts an upward force on your body, according to Newton. This connection produces two forces: one on the chair and one on your body. Newton’s third law of motion deals with these two forces, which are referred to as action and reaction forces.