Physics Basics – Study Notes
(For Andhra Pradesh TET – General Awareness & Current Affairs)
Goal of these notes:
- Understand everyday ideas that are the building blocks of physics.
- Use simple words, short sentences, and everyday analogies.
- No heavy jargon – just the concepts you’ll need for the exam.
1. What is Physics?
Physics is the study of how things move, how forces work, and how energy behaves.
Think of it as the rules of the physical world that explain why a ball rolls, why a light turns on, or why a magnet sticks to a refrigerator.
2. Core Concepts
| Concept | Everyday Analogy | Tiny Example |
|---|---|---|
| Force | A push or pull you feel when you open a door | Pushing a shopping cart |
| Mass | How heavy something is (not the same as “weight”) | A 5 kg bag of rice |
| Speed | How fast you’re moving | A car going 60 km/h |
| Acceleration | How fast the speed changes | A car speeding up from 0 to 60 km/h in 5 s |
| Energy | The ability to do work | A battery that powers a toy car |
| Work | Force applied over a distance | Pushing a book 2 m across a table |
| Power | How fast work is done | Lifting a 10 kg bag in 2 s vs. 10 s |
| Gravity | The invisible pull between two masses | An apple falling from a tree |
| Electricity | Flow of tiny charged particles | Light bulb turning on |
| Magnetism | Invisible force that can attract or repel | Magnet sticking to a fridge |
| Waves | Ripples that carry energy | Sound from a speaker, light from the sun |
3. Force & Motion
-
Force = Push or Pull.
Every time you push a door, you’re applying a force. -
Newton’s First Law (Simplified).
An object stays still or keeps moving at a constant speed unless a force changes that motion.
Analogy: A bowling ball on a flat floor stays still until you roll it. -
Newton’s Second Law (Simplified).
The bigger the mass, the bigger the push needed to change its speed.
Analogy: Pushing a heavy truck is harder than a bike. -
Newton’s Third Law (Simplified).
Every push has an equal and opposite reaction.
Analogy: When you jump off a boat, the boat moves backward.
4. Energy, Work & Power
| Term | Simple Definition | Example |
|---|---|---|
| Energy | Ability to do work. | A battery in a flashlight. |
| Work | Force acting over a distance. | Moving a box 3 m across the floor. |
| Power | Work done per unit time. | Lifting a weight quickly vs. slowly. |
Tiny Example:
If you lift a 10 kg bag 2 m in 4 s, you did work = force (≈ 100 N) × distance (2 m) = 200 J.
Power = 200 J ÷ 4 s = 50 W (watts).
Doing the same lift in 2 s gives 100 W power.
5. Simple Machines
| Machine | What It Does | Everyday Example |
|---|---|---|
| Lever | Turns a small force into a larger one. | Seesaw on a playground. |
| Inclined Plane | Makes lifting easier. | A ramp to load a truck. |
| Wheel & Axle | Reduces friction. | A car wheel. |
| Pulley | Changes direction of force. | Elevator cables. |
| Screw | Turns rotation into forward motion. | A bottle cap. |
| Wedge | Splits objects apart. | A knife cutting bread. |
6. Gravity
- What It Is: The pull that attracts two masses toward each other.
- Everyday Life: Apples fall from trees, you