# Five Important Science Laws Every Student Must Know

“In Science, laws are a starting place from where scientists can ask questions like why and how?” says Peter Coppinger, an associate professor of biology and biomedical engineering at the Rose-Hulman Institute of Technology. A scientific law is a description of an observed phenomenon. It doesn’t explain what causes the phenomenon and why it exists. A scientific theory, on the other hand, describes the observed phenomenon.

## Five Important Laws in Science

Every law in Science has its significance and benefits, but in this article, we will list five laws that are ubiquitous and are applied to many everyday activities.

### Newton’s Laws of Motion

Newton’s three laws of motion define the relationship between the acceleration of an object and the force acting on them. They also govern how the motion of the objects change.

The laws of motion help us understand how objects behave when they stand still, when they move and when forces act on them. The three laws of motion state the following:

• Newton’s First Law of Motion: “The first law of motion states that a body at rest or uniform motion will continue to be at rest or uniform motion until and unless a net external force acts on it.”
• Newton’s Second Law of Motion: “The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.”
• Newton’s Third Law of Motion: “For every action, there is an equal and opposite reaction.”

These three laws can be applied to numerous situations to solve problems of motion.

### Conservation of Mass and Energy

The law of conservation of energy states that the total amount of energy remains constant in an isolated system. It indicates that energy can neither be created nor destroyed, but can only be transformed from one form to another.

The law of conservation of mass states that the total amount of mass remains constant in an isolated system despite the chemical and physical reactions that may take place.

The principle of mass conservation is widely used in fields such as Chemistry, fluid dynamics and mechanics. The principle of energy conservation helps us solve the equations for velocity, distance, or other parameters that depend on energy.

### Ohm’s Law

Ohm’s Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. The law holds only if the temperature and other physical factors remain constant. Ohm’s Law fails to explain the behaviour of semiconductor devices because of their non-linearity (ratio of voltage to current doesn’t remain constant for variations in voltage). Ohm’s Law is used to validate static values in the electric circuit, such as voltage and electric current.

### Laws of Thermodynamics

Thermodynamics is a branch in science that describes how thermal energy is converted to and fro from other forms of energy and how this affects the matter. The fundamental principles of thermodynamics are expressed in the form of four laws. The four laws of thermodynamics state the following:

• Zeroth Law of Thermodynamics: “ If two bodies are individually  in equilibrium with a third body, then the first two bodies are also in equilibrium with each other.”
• First Law of Thermodynamics: “Energy can neither be created nor destroyed it can only be transformed from one form to another.”
• Second Law of Thermodynamics: “The entropy in an isolated system always increases. Any isolated system spontaneously evolves towards thermal equilibrium—the state of maximum entropy of the system.”
• Third Law of Thermodynamics: “The entropy of a system approaches a constant value as the temperature approaches absolute zero.”

### Law of Universal Gravitation

Newton’s law of universal gravitation states that any particle of matter in the universe attracts any other with force varying directly as the product of the masses and inversely as the square of the distance between them. It is a universal law because it applies to all bodies having mass.

These were some of the essential laws that every student must know. Hope you enjoy learning them!