↑ Science
Physics is the study of matter, energy, and how they interact.
It explains the fundamental laws of nature that govern motion, forces, energy, and the structure of matter.
- It answers
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Why things move.
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How energy is transferred.
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How the universe works at every scale.
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Why Study Physics?
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Physics is the foundation of other sciences like chemistry, biology, and astronomy.
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It helps in developing technology, from smartphones to rockets.
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It improves problem-solving and critical thinking skills.
Branches of Physics
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Mechanics: Motion, forces, energy (Newton’s Laws).
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Thermodynamics: Heat, temperature, and energy transfer.
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Waves and Sound: Vibrations, sound, and wave behavior.
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Optics: Light, lenses, mirrors, reflection/refraction.
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Electricity and Magnetism: Circuits, electric fields, magnets.
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Modern Physics: Quantum physics, relativity, atomic theory.
The Scientific Method in Physics
- Physics relies on The Scientific Method, which includes
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Observation
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Question
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Hypothesis
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Experiment
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Data Collection
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Analysis
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Conclusion
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Physical Quantities and Units
Physics uses measurements to describe and predict phenomena.
- Base Quantities
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Length - meters m.
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Mass - kilograms kg.
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Time - seconds s.
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Temperature - kelvin K.
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Electric current - amperes A.
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Electric charge - coulombs C.
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Electric potential - volts V.
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SI Units (International System of Units)
The SI system is the standard for measurements.
- Example
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Distance = meters (m)
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Mass = kilograms (kg)
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Time = seconds (s)
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Force = newtons (N) (Derived unit)
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Scalars vs. Vectors
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Scalar: Quantity with magnitude-only (size)
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Example: Speed = 60 km/h
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Vector: Quantity with magnitude and direction
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Example: Velocity = 60 km/h north
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Measurement and Instruments
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Length → Ruler, Vernier Caliper, Micrometer
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Mass → Balance
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Time → Stopwatch
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Temperature → Thermometer
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Electric Current → Ammeter
Accuracy, Precision, and Errors
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Accuracy: How close a measurement is to the true value.
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Precision: How consistent repeated measurements are.
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Error types:
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Systematic error: Consistent, repeatable error.
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Random error: Unpredictable variations in measurements.
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Graphs and Data Representation
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Line Graphs: Show changes over time or relationships.
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Bar Graphs: Compare quantities.
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Pie Charts: Show parts of a whole.
Basic Mathematical Skills for Physics
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Algebra (solving equations)
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Ratios and Proportions
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Graphs and Slopes (understanding relationships)
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Trigonometry (basic sine, cosine, tangent)
Physics is a science derived from mathematics just like every other science.
