Introduction to Physics

Introduction to Physics – Study Notes

1. What Is Physics?

• Definition: The scientific discipline that studies matter, energy, and the fundamental forces that govern their interactions.
• Goal: To describe how the universe works through concise, testable models and laws.
• Scope: From sub‑atomic particles to galaxies; from static objects to dynamic processes.

2. Core Concepts & Terminology

3. The Scientific Method in Physics

1. Observation – Gather data from experiments or nature.
2. Question – Identify a specific problem or phenomenon.
3. Hypothesis – Propose a testable explanation.
4. Prediction – Derive consequences that follow from the hypothesis.
5. Experiment – Design controlled tests; collect quantitative results.
6. Analysis – Compare predictions with data; use statistics to assess agreement.
7. Conclusion – Accept, modify, or reject the hypothesis; publish findings.

4. Fundamental Branches

5. Fundamental Laws (Selected)

1. Newton’s Three Laws of Motion

   • First: Inertia – a body remains at rest or in uniform motion unless acted upon by a net force.
   • Second: ( \mathbf{F} = m\mathbf{a} ) – force equals mass times acceleration.
   • Third: Action–reaction – forces occur in equal and opposite pairs.

2. Law of Universal Gravitation
   [ F = G\frac{m_1 m_2}{r^2} ]

   • (G) = gravitational constant, (r) = distance between centers.

3. Conservation Principles

   • Energy –