# Physics - Basic and Fundamental Physics Concepts

#### Academic Questions in PhysicsPlease check out our Test Your Knowledge page to see all Questions and Answers A natural force that pulls a body towards the center of the earth is termed _____. A. Centripetal force B. Centrifugal force C. Black hole D. Average acceleration E. Gravity F. Momentum A Greek letter that expresses density is _____. A. Alpha_d B. Beta_d C. Theta_d D. rho E. dho F. dhr A glass of water has a higher density than an exact glass of oil. A. True B. False An 🍎 apple 🍎 falling from a tree has an unbalanced force. A. True B. False Force is a quantity measured in _____. A. Kilogram B. Gravity C. Incandescence D. Meter per second square (ms-1) E. Mole F. Newton Heat transfer indicates two systems of varying temperatures and will always be transferred from a region with lower temperature to another with higher temperature. A. True B. False Heat can be created. A. True B. False Temperature is defined as the measure or ability of an object or substance to transfer heat energy to another object or substance. A. True B. False ### What is physics?

Physics is defined as the scientific study of matter and the movement of matter through the space and time of the universe.

Note: Physics also explains how matter interact with each other.

In this article, we would look into the 4 basic and most fundamental physics concepts that will help you to better understand this subject. These are:

#### 1. The Laws of Motion (Classical Mechanics)

You may have probably heard the story of Sir Isaac Newton sitting under an apple tree and formulating the basic laws of motion. Although this story of Newton sitting under an apple tree isn't exactly true, Sir Isaac Newton actually made and explained the three fundamental laws of classical mechanics (also referred to as Newton's laws of motion).

They are stated thus:

An object at rest will continue in its state of rest; while an object in uniform motion will continue in a straight line, unless an external force acts on it.

Newton's First Law of Motion.

The rate of change of momemtum is proportional to the applied force and will take place in the direction of that force.

Newton's Second Law of Motion.

To every action, there is an equal and opposite reaction.

Newton's Third Law of Motion.

If we looked deeply into these laws, we will see that they apply to our everyday life. For instance:

• when an egg is put on a flat surface, the egg remains still unless someone touches it (or an external force acts on it).
• On a hilly surface, gravity acts upon an object and pulls it downhill continuously, unless an opposite force (greater than gravity itself) acts against gravity.
• Plase read on Gravity here.

• Finally, if we hit our head against a wall, we will feel some pain simply because the wall exerts an equal and opposite force in return.

#### 2. Electromagnetism

Electromagnetism refers to the forces generated by electrons found in certain atoms. For instance, magnets have electrons that are configured in such a way that they exert force on other charged electrons.

The very reason why a magnet will attract a nail (and NOT a paper) is based on the fact that magnets exert energy on other “charged particles”. In this case, the particles found around the nail will exist as charged particles.

We use the term Photons to describe the force carried by an electromagnetic field.

Note: Electromagnetic radiation makes up much of our daily lives and these includes visible light, radio waves, x rays, and so on.

Electromagnetic forces have the capacity to generate charges and electricity and we may have come accross this process as kids (probably when a paper is used to attract things).

#### 3. Relativity The work of Albert Einstein opened up the theory of special relativity when he discovered that the speed of light in a vacuum does not depend on the motion of all observers.

General relativity is often described with the analogy of a moving car. It was expanded in the early 1900s when Albert Einstein created special relativity.

#### 4. Thermodynamics

The study of thermodynamics revolves around the relationship between heat, temperature, energy and mechanical work; and these can be summarised under the 4 laws of Thermodynamics (Numbered zero through three).

##### Below are the 4 laws of thermodynamics:

Zeroth law of thermodynamics – If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

1st law of thermodynamics – Energy can neither be created nor destroyed but can be changed from one form to another.

2nd law of thermodynamics – The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.

3rd law of thermodynamics – As temperature approaches absolute zero, the entropy of a system approaches a constant minimum. Alfred Ajibola is a Medical Biochemist, a passionate Academician with over 7 years of experience, a Versatile Writer, a Web Developer, a Cisco Certified Network Associate and a Cisco CyberOps Associate.

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