SCIENCE IMPORTANT FORMULAE CLASS - 9
Important Formulae for class 9 science
Updated for new syllabus - 2026
Class 9 science Important Formulae
The Important Science Formulae section at Saraswat Academy provides a complete collection of chapter-wise scientific formulas based on the latest CBSE Syllabus 2026–27. These formulas are carefully selected from the NCERT textbooks and presented in a simple, easy-to-understand format for quick learning and revision. They help students strengthen their conceptual understanding, solve numerical problems accurately, and improve problem-solving speed in Physics, Chemistry, and other formula-based topics. Regular practice of these formulas is essential for homework, class tests, unit tests, practical examinations, half-yearly examinations, annual examinations, and CBSE board examinations. This page serves as a quick revision resource, enabling students to recall important formulas confidently and perform better in both school and competitive examinations.
Regular revision of scientific formulas helps students strengthen conceptual understanding, improve numerical problem-solving skills, and reduce errors in calculations during examinations. Whether you are preparing for school assessments, practical examinations, or CBSE board exams, these chapter-wise science formula sheets provide a quick and effective revision resource. Students are encouraged to practise these formulas alongside NCERT questions, exemplar problems, practical-based questions, competency-based questions, and previous years' board questions to develop scientific reasoning, enhance accuracy, and achieve excellent marks in Science.
Important Formulae: Science Class - 9
Chapter -1
Important Formulae & Mathematical Relations
1. Velocity Formula
Velocity = Distance ÷ Time
v = d / t
Used to describe the motion of an object.
2. Total Minutes in One Day
60 × 24 = 1440 minutes
3. Estimated Number of Breaths Per Day
Breaths per minute = 12–15
Minutes per day = 1440
Estimated breaths per day ≈ 20,000
4. Estimated Air Breathed Per Day
Volume of one breath ≈ 0.5 litre
Total air breathed per day ≈ 20,000 × 0.5
≈ 10,000 litres/day
5. Balloon Estimation
3 balloons/minute × 2 litres/balloon × 1440 minutes/day
≈ 8640 litres/day
6. Speed of Light
c = 299,792,458 m/s
Symbol: c
Important Scientific Symbols
| Quantity | Symbol |
|---|---|
| Mass | m |
| Velocity | v |
| Force | F |
| Electric Current | I |
| Speed of Light | c |
Important SI Unit Facts
- Use standard SI units everywhere.
- Kilogram (kg) is the SI unit of mass.
- Metre (m) is the SI unit of length.
- Second (s) is the SI unit of time.
- Using SI units avoids calculation errors.
Important Definitions
Model
A simplified representation of a real system that keeps only the important details required to solve a problem.
Scientific Law
A law describes a regular pattern observed in nature. It tells what happens.
Scientific Theory
A theory explains why something happens. It is based on repeated evidence and experiments.
Scientific Principle
A broad scientific idea that helps explain or understand different situations.
Important Chapter Notes
- Science begins with curiosity and observation.
- Scientific models simplify complex systems.
- Good models ignore unnecessary details.
- Science uses precise language.
- Mathematics is the language of science.
- Understand the situation before using equations.
- Use standard SI units for all measurements.
- Scientific predictions are based on evidence, not guesses.
- Predictions must be tested through experiments.
- Scientific theories can change if new evidence is found.
- Science accepts correction based on evidence.
- Approximation helps check whether answers are reasonable.
- Science connects Physics, Chemistry, Biology, Earth Science and Mathematics.
- Real-life problems often require knowledge from multiple branches of science.
- Scientific thinking is useful in everyday life.
Most Important Facts for Exams
- Science uses observation, experimentation and evidence.
- Models simplify reality.
- Scientific laws describe patterns.
- Theories explain observations.
- Principles are broad scientific ideas.
- Predictions are evidence-based.
- Approximation is an important scientific skill.
- Always use SI units.
- Science is always open to improvement.
- Scientific thinking relies on logic, evidence and reasoning.
One Minute Revision
- Observation → Model → Measurement → Mathematics → Prediction → Experiment → Evidence
- Model = Simplified system
- Law = What happens
- Theory = Why it happens
- Principle = General scientific idea
- Science never accepts claims without evidence.
- SI units make measurements universal.
- Approximate estimation helps detect impossible answers.