12 Fundamental Laws of Physics Everyone Should Know
Fundamental Laws of Physics: Basic Physics laws significantly influence our understanding of reality as they are formulated and validated through factual evidence. Everything in our surroundings is interconnected with the principles of physics. Therefore, Physics is considered the bedrock of all natural sciences, providing crucial insights into how the universe functions.
Understanding the fundamental laws of Physics is essential for students and science enthusiasts to grasp the underlying principles that govern our world. Additionally, gaining a thorough command of fundamental principles of Physics is crucial for excelling in various competitive exams like JEE, NEET, and more.
12 Fundamental Laws of Physics
Physical laws are derived from extensive scientific observations and repeated experiments conducted under various conditions. These conclusions are universally accepted. The principles governing our world are articulated by scientists in the form of these physical laws.
Here are 12 essential physics laws explained with relevant examples:
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Newton's Laws of Motion
Sir Isaac Newton invented three laws of Physics. One can relate to these Physics Laws in everyday life. Here is the explanation of all these laws with relatable examples:
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Newton's First Law (Law of Inertia)
An object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. This law introduces the concept of inertia, highlighting that an object's state of motion remains constant unless disturbed by an external force.
Example: A book on a table will stay at rest until someone pushes it. Similarly, a soccer ball will keep rolling until friction or another force stops it.
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Newton's Second Law
The force acting on an object is equal to the mass of the object multiplied by its acceleration (F = ma). This law explains the relationship between force, mass, and acceleration, providing a fundamental equation in mechanics.
Example: Pushing an empty shopping cart is easier than pushing a full one. The greater the mass of the cart, the more force needed to accelerate it.
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Newton's Third Law
For every action, there is an equal and opposite reaction. This principle explains the interactions between objects, stating that forces always come in pairs and act on different objects.
Example: When you jump off a small boat, you push the boat backwards. The force you use to jump forward is matched by an equal force pushing the boat in the opposite direction.
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Einstein's Theory of Relativity
Einstein's Theory of Relativity includes both General Relativity and Special Relativity. Here is the explanation of both these Physics theories with examples:
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Special Relativity
It deals with objects moving at constant speeds, particularly those approaching the speed of light. It introduced the famous equation E=mc², showing that energy (E) and mass (m) are interchangeable.
Example: GPS satellites account for both the speed at which they orbit Earth and the gravitational time dilation due to their altitude. Without relativity, the timing errors would make GPS inaccurate.
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General Relativity
It is based on the Special Relativity theory. According to this theory, large objects distort the fabric of spacetime, causing other objects to follow curved trajectories.
Example: The bending of light from a star by the Sun's gravity, known as gravitational lensing. One can observe this phenomenon during a solar eclipse.
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Law of Universal Gravitation
This Fundamental law of Physics was invented by Newton. It explains that every object attracts every other object with a force directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. This law explains the gravitational attraction between two masses.
Example: The reason why objects fall to the ground when dropped is due to Earth's gravitational pull.
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Zeroth Law of Thermodynamics
According to this Physics law, if two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other. This law establishes the concept of temperature and thermal equilibrium.
Example: If a cup of hot coffee is at the same temperature as a metal spoon and the spoon is at the same temperature as the surrounding air, then the coffee, spoon, and air are all at the same temperature.
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Conservation Laws
Conservation Laws include the following two Physics laws:
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Law of Conservation of Energy
Energy cannot be created or destroyed; it can only be transformed from one form to another. This principle explains that the total energy in an isolated system remains constant.
Example: When riding a bicycle downhill, the potential energy due to rider’s height is converted into kinetic energy as they gain speed.
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Law of Conservation of Momentum
The total momentum of a closed system remains constant if no external forces are applied to it. This law is crucial for analysing collisions and other interactions in physics.
Example: When playing pool, the momentum of the cue ball is transferred to the target ball, demonstrating the conservation of momentum.
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Coulomb's Law
The force between two charged particles is directly proportional to the product of the charges. Additionally, it is inversely proportional to the square of the distance between them. This law explains the electrostatic force between charges.
Example: Rubbing a balloon on one’s hair transfers electrons, giving the balloon a charge. The balloon can then attract small bits of paper due to electrostatic force.
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Faraday's Law of Electromagnetic Induction
A change in the magnetic field within a closed loop induces an electromotive force (EMF) in the wire forming the loop. This principle forms the base of electric generators and transformers functions.
Example: Electric generators work on this principle, converting mechanical energy into electrical energy by rotating a coil in a magnetic field.
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Ohm's Law
The current passing through a conductor between two points is directly proportional to the voltage running across the two points and inversely proportional to the resistance between them. The formula for Ohm’s law is (V = IR). This fundamental law of Physics is crucial in understanding electrical circuits.
Example: Turning on a light switch applies a voltage across the light bulb, causing current to flow and the bulb to light up, provided the resistance of the bulb remains constant.
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Planck's Law
Energy is quantized and can be emitted or absorbed in discrete amounts called quanta. This law, introduced by Max Planck, is a cornerstone of quantum mechanics and explains phenomena at the atomic and subatomic levels.
Example: The colour of light emitted by a heated metal changes with temperature due to quantized energy levels.
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Bernoulli’s Principle
Bernoulli’s principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. This principle explains how aeroplanes achieve lift and why the pressure decreases as fluid velocity increases.
Example: Airplane wings are designed so that air flows faster over the top surface than the bottom, creating lower pressure above the wing and providing lift.
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Hooke’s Law
Hooke’s Law states that the force needed to compress or extend a spring by some distance is proportional to that extended or compressed distance. This law is fundamental in the study of elasticity and material science.
Example: The more you stretch a rubber band, the harder it pulls back. This principle is also used in measuring forces with spring scales.
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Archimedes' Law
Archimedes' Law states that a body immersed in a fluid experiences a buoyant force equal to the weight of the fluid displaced by the body. This principle explains why objects float or sink in water.
Example: When you get into a bathtub, the water level rises. The buoyant force you experience is equal to the weight of the water displaced by your body.
Exploring the 12 fundamental concepts of physics provides a comprehensive foundation for understanding the natural world. These concepts, including Discovering Physics Fundamentals, explain the principles governing matter, energy, and their interactions. From mechanics to thermodynamics, electricity to quantum mechanics, each concept reveals intricate patterns and behaviours that shape our universe.
Candidates wanting to strengthen their grasp of fundamental Physics concepts must join PW Gulf Foundation Online Coaching. PW Gulf faculties provide in-depth explanations of various physics laws and their application to solve real-life problems, strengthening students' knowledge and problem-solving skills.
Fundamental Laws of Physics FAQs
Q1. How many laws are there in Physics?
Ans. There are nearly 34 important laws in Physics.
Q2. Who is the father of physics?
Ans. Sir Isaac Newton is the father of Physics.
Q3. What is the hardest law of physics?
Ans. Every law of Physics requires in-depth understanding. Most students find Einstein’s General Relativity theory most challenging to understand.
