Core Concepts in Physics: Energy, Forces, and Circuits
Energy and Work Done
Defining Work, Power, and Energy
- Work Done: Energy transferred when a force moves an object over a distance.
- Power: The rate at which energy is transferred (how quickly).
- Energy Stores: Kinetic, gravitational potential, elastic potential, thermal, chemical, and nuclear.
- Energy Transfers: Occur via mechanical work, electrical work, heating, and radiation.
Efficiency in Energy Transfer
The higher the efficiency, the less energy is wasted (often as heat or sound).
Note: No machine is 100%
Read MoreEssential Definitions in Physics, Optics, and Cosmology
Fundamental Concepts in Physics
Sound and Wave Propagation
Speed of Sound (Sound Velocity)
The sound velocity is the speed of propagation of sound waves, a type of longitudinal mechanical wave produced by pressure variations of the medium. These pressure variations (captured by the human ear) contribute to the brain’s perception of sound. Sound does not travel through a vacuum because there are no atoms through which the waves can pass. (330 km / s)
Sound
The sensation produced in the ear by the vibration
Read MorePhysics Fundamentals: Key Concepts, Formulas, and Energy Scales
Energy & Power
• Energy: ability to do work; conserved; transforms among heat, chemical, mechanical, electrical, nuclear, etc.
• Power: rate of energy use; determines how fast work is done or energy is converted.
Units & Conversions
• calorie (cal): energy to raise 1 g water by 1 °C ~ Calorie (food Cal) = 1 kcal = 1 000 cal ~ joule (J): SI unit; 1 J = 1 kg·m²/s²
• kilowatt-hour (kWh): industrial/domestic unit; 1 kWh = 3.6 MJ ≈ 1 000 Cal
• household uses ~12 000 kWh/yr
Typical Energy
Read Moreਪੰਜਾਬੀ ਵਿਆਕਰਨ: ਨਾਂਵ, ਪੜਨਾਂਵ, ਕਿਰਿਆ ਅਤੇ ਕਿਰਿਆ ਵਿਸ਼ੇਸ਼ਣ
ਪੰਜਾਬੀ ਵਿੱਚ ਨਾਂਵ (Noun)
ਪੰਜਾਬੀ ਵਿੱਚ ਨਾਂਵ (Noun) ਉਹ ਸ਼ਬਦ ਹੁੰਦਾ ਹੈ ਜੋ ਕਿਸੇ ਵਿਅਕਤੀ, ਸਥਾਨ, ਚੀਜ਼, ਵਿਚਾਰ, ਗੁਣ ਜਾਂ ਅਵਸਥਾ ਦਾ ਨਾਮ ਦੱਸਦਾ ਹੈ। ਇਹ ਵਾਕ ਵਿੱਚ ਕਰਤਾ ਜਾਂ ਕਰਮ ਵਜੋਂ ਵਰਤਿਆ ਜਾਂਦਾ ਹੈ।
ਨਾਂਵ ਦੀਆਂ ਕਿਸਮਾਂ (Types of Noun)
ਪੰਜਾਬੀ
Read MoreWave, Sound, and Light Physics Concepts
Wave Fundamentals
Wave Definition
A disturbance traveling through a material medium due to the vibration or oscillation of its particles.
Wave Types by Medium
- Mechanical Waves: Require a medium (natural environment) for propagation.
- Electromagnetic Waves: Do not require a medium; can travel through a vacuum.
Wave Types by Direction
- Transverse Waves: Particles vibrate perpendicular to the direction of propagation, forming peaks and valleys.
- Longitudinal Waves: Particles vibrate in the same direction as propagation,
Fundamental Physics Concepts: Questions and Solutions
Natural Phenomena for Time Standards
Q.1 Name several repetitive phenomena in nature for time standard.
- Earth-Sun System
- Moon-Earth System
- Human Pulse
- Quartz Crystal Vibration
Pendulum as a Time Standard: Drawbacks
Q.2 Drawbacks of using a pendulum as a time standard.
- Length and gravitational acceleration (g) vary.
- Friction affects its motion.
- Air resistance influences its period.
Kilogram vs. Mole: Understanding Mass and Quantity
Q.3 Why use both kilogram (kg) and mole?
- Kilogram (kg): Represents the mass of