Physics and Measurement

Physics is one of the most critical branches of science that deals with fundamental phenomena. These include the laws of motion, laws of nuclear fission, laws of electrodynamics, and so on.

In order to apply the laws and concepts of Physics, it is important to know about physical quantities and measurement, measurement history, basic measurement units, and other different kinds of laws. 

Definitions of  Physics and Measurement

Physics is a branch of science that plays a significant role in almost all domains of life. From the tides in the ocean to the moon’s orbit, everything can be studied under physics. 

Measurement is one of the most important and fundamental physics concepts without which there might be no value of theories, experiments, or other tests recorded. Without measuring, it would be nearly impossible for a scientist to determine results. Measurement includes several tools to describe how many or how much of something is there. For this, scientists are primarily dependent on the metric system, which was first developed in the 1790s in France. 

Units of Measurement 

There are seven basic units of measurement used by scientists worldwide. These include – 

• Length – Metre (m)

• Time – Second (s)

• Mass – Kilogram (kg)

• Electric current – Ampere (A)

• Temperature – Kelvin (K)

• Amount of a substance – Mole (mol)

• Luminous Intensity – Candela (cd)

Derived Units of Measurement 

Basic Laws of Physics 

Newton’s First Law of Motion 

According to Newton’s first law of motion, no object on this planet can start, stop, or change its directions by itself. They require an external force or the force from outside to make any movement or bring change. The other name of Newton’s first law of motion is the law of inertia. 

Newton’s Second Law of Motion

According to Newton’s second law of motion, the total force acting upon the body is the same as the product of its acceleration and mass. It can be written as F = ma. 

Newton’s Third Law of Motion

Newton’s third law of motion talks about what happens to the body when it exerts force onto another body. Every time the two-body come closer to each other and interact, the force applied is opposite in direction and equal in magnitude. 

Law of Friction 

Friction has mainly five different laws. These are as follows:  

• Friction is independent of the contact area in case there is enough area of contact

• The friction of the object moving is perpendicular and proportional to the normal face. 

• The object experiencing the friction is highly dependent on the surface nature it comes in contact with. 

• The velocity highly determines the kinetic friction. 

• The static friction coefficient is always greater than the kinetic friction coefficient.

Law of Rutherford Atomic Model

• The Rutherford atomic model states that the charged electrons negatively surround the entire nucleus. He also believed that electrons surrounding the nucleus were revolving around it at an extremely high speed in a circular motion, called orbits. 

• Most of the atom’s mass and positively charged particles were present in exceptionally small volumes, the nucleus.

• Nucleus being positively charged; however, electrons being charged positively, both were held together tightly by an electrostatic force of attraction. 

Conclusion 

In this introduction to physical quantities and measurement, we covered the history of measurement, seven base units used to measure physics, derived units, and other related topics.