Grade 7
  1. Introduction to Physics  1.1. Definition and scope of physics  1.2. Importance of Physics in Daily Life and Technology  1.3. Scientific method and its applications in physics  1.4. Measurement and Experiments in Physics  1.5. Branches of Physics and their Applications  1.6. Relation of physics with other sciences
  2. Measurement and units  2.1. Fundamental and derived quantities  2.2. SI units and unit conversions  2.3. Length measuring instruments and tools used  2.4. Measuring the difference between mass and weight  2.5. Measuring time with accuracy  2.6. Measuring the Volume of Regular and Irregular Objects  2.7. Measuring Temperature and Temperature Scales  2.8. Accuracy, Precision, and Significant Figures  2.9. Errors in Measurement and How to Reduce Them  2.10. Estimates and approximations in scientific calculations  2.11. Standard form and order of magnitude
  3. Speed and Force  3.1. Introduction to motion and rest  3.2. Types of motion - uniform and non-uniform  3.3. Scalars and vectors in motion  3.4. Speed, Velocity, and Acceleration  3.5. Distance-time and velocity-time graphs  3.6. Newton's first law of motion (law of inertia)  3.7. Newton's second law of motion (force and acceleration)  3.8. newton's third law of motion  3.9. Types of forces - contact and non-contact forces  3.10. Effect of forces on motion  3.11. Friction – types, effects and applications  3.12. Gravity, free fall and gravitational acceleration  3.13. Circular motion and centripetal force  3.14. Application of Newton's laws in real life
  4. Energy, Work and Power  4.1. Definition and forms of energy  4.2. Potential and Kinetic Energy  4.3. Law of conservation of energy  4.4. Energy transformations in everyday life  4.5. Work done by force and its calculation  4.6. Power - Definition and Calculation  4.7. Simple Machines and Mechanical Advantage  4.8. Efficiency and energy losses of machines  4.9. Renewable and non-renewable energy sources
  5. Heat and temperature  5.1. Difference Between Heat and Temperature  5.2. Thermometer and temperature scale (Celsius, Kelvin, Fahrenheit)  5.3. Expansion and contraction of solids, liquids and gases  5.4. Heat transfer methods – conduction, convection and radiation  5.5. good and bad conductors of heat  5.6. Applications of heat transfer in daily life  5.7. Specific heat capacity and its applications  5.8. Latent heat and change of state  5.9. Thermal equilibrium and heat exchange  5.10. effect of heat on matter
  6. Lighting and Optics  6.1. Nature and properties of light  6.2. Reflection of light and laws of reflection  6.3. Image formation by plane and curved mirrors  6.4. Refraction of light and the laws of refraction  6.5. Lenses – convex and concave, image formation  6.6. Optical instruments – microscope, telescope, camera  6.7. Dispersion of light and formation of spectrum  6.8. Human eye, vision defects and their correction  6.9. Applications of optics in daily life  6.10. Total internal reflection and its applications
  7. Sound and waves  7.1. Nature and properties of waves  7.2. Production and propagation of sound  7.3. Characteristics of sound waves – frequency, amplitude, wavelength  7.4. Speed of sound in different mediums  7.5. Reflection of sound – echo and reverberation  7.6. Ultrasound and its applications  7.7. Doppler effect in sound waves  7.8. Noise pollution and its effects  7.9. Applications of sound in medicine and industry
  8. Electricity and Magnetism  8.1. Electric charge and static electricity  8.2. Electrical conductors and insulators  8.3. Electric current, voltage and resistance  8.4. Ohm's law and its applications  8.5. Electrical Circuits - Series and Parallel Circuits  8.6. Electric power and energy consumption  8.7. Safety precautions in the use of electricity  8.8. Properties of magnets and magnetic fields  8.9. Electromagnets - How They Work and Their Uses  8.10. Relation between electricity and magnetism (electromagnetic induction)  8.11. Applications of electromagnetism in technology  8.12. Earth's magnetic field and its effects
  9. Matter and its properties  9.1. Classification of matter- solid, liquid and gas  9.2. Properties of different states of matter  9.3. Kinetic theory of matter  9.4. Changes in the state of matter and their causes  9.5. Expansion and contraction of substances  9.6. Density and its calculation  9.7. Pressure in solids, liquids and gases  9.8. Atmospheric pressure and its effects  9.9. Applications of pressure in daily life  9.10. Buoyancy and Archimedes' principle
  10. Space Science and Solar System  10.1. Introduction to Astronomy  10.2. Solar System - Planets and their Characteristics  10.3. Sun - structure and energy production  10.4. Moon - phases and its effect on Earth  10.5. Rotation and revolution of the earth  10.6. Solar and lunar eclipses  10.7. Gravity in space and its role in orbits  10.8. Artificial satellites and their uses  10.9. Space exploration and modern discoveries  10.10. Asteroids, comets and meteors  10.11. Life beyond Earth - Possibilities and Theories
  11. Environmental Physics  11.1. Impact of physics on environmental science  11.2. Renewable and non-renewable energy sources  11.3. Energy conservation and efficiency  11.4. Climate change and its effects on Earth  11.5. Air, water and soil pollution – causes and effects  11.6. Greenhouse effect and global warming  11.7. Sustainable development and environmental protection  11.8. Role of Physics in Weather and Climate Studies

Grade 7 → Measurement and units ↓


Fundamental and derived quantities


In the world of physics, measurement is a cornerstone. It allows scientists and students to describe the world in numbers, bringing clarity and precision to concepts that might otherwise be abstract or hard to understand. To explore the field of measurement, we must first understand the building blocks: fundamental and derived quantities.

Understanding the quantities

Before diving into fundamental and derived quantities, let us first understand what a 'quantity' is in physics. In scientific terms a quantity is any property of an object or phenomenon that can be measured. Quantities are typically expressed by a number and a unit, such as 20 m, where '20' is the number and 'm' is the unit.

Fundamental quantities

Fundamental quantities are the basic units of measurement on which other quantities depend. These are considered the basis of all physical measurements. In other words, these are the building blocks of measurement. There are seven fundamental quantities adopted in the International System of Units (SI). They are:

  • Length – represented by meter (m).
  • Mass – represented by kilogram (kg).
  • Time is represented by second (s).
  • Electric current – represented by amperes (A).
  • Temperature - represented by Kelvin (K).
  • The amount of a substance is represented by moles.
  • Light intensity - expressed in candela (cd).

Visual example: a ruler

Think of a simple ruler. It helps you measure basic quantities such as length. When you measure a book and find that it is 20 cm wide, you are using a basic quantity because you are only concerned with one dimension: length.

0 cm 10 cm 20 cm 30 cm 40 cm 50 cm

Derived quantities

On the other hand, derived quantities are those that are derived from basic quantities through mathematical operations such as multiplication and division. They depend on one or more basic quantities to exist. For example, speed is a derived quantity because it depends on both length and time. Derived quantities are formed by combining basic units. Some common derived quantities are as follows:

  • Area - The combination of length and width, measured in square metres (m2 ).
  • Volume - The combination of length, width, and height, measured in cubic metres (m3 ).
  • Speed - A combination of length and time, measured in metres per second (m/s).
  • Force – measured in newtons (N), which is a combination of mass and acceleration (kg m/s2 ).
  • Pressure - force per unit area, measured in pascals (Pa).
  • Energy – measured in joules (J), includes mass, velocity, and acceleration (kg m2 / s2 ).

Visual example: speed calculation

Imagine that your friend is cycling from home to school, and you want to measure how fast she cycles. This involves the basic quantities of length and time. If she cycles 1,000 meters in 200 seconds, we need to use the formula for speed:

Speed = Distance / Time
Speed = 1,000 meters / 200 seconds = 5 meters/second
Cyclist speed: 5 m / s

Relationships and examples

To better understand how fundamental and derived quantities are connected, consider the following relationships:

Example: Calculating area

Area is a derived quantity because it depends on two measurements of the basic quantity of length. For example, if a rectangular garden is 50 m long and 20 m wide, the area will be:

Area = Length × Width
Area = 50 meters × 20 meters = 1,000 square meters (m2)
Area = 1,000 m2

Example: Calculating force

Force is another example of a derived quantity. In physics, it is defined as mass times acceleration. If a car has a mass of 1,000 kg and moves at a speed of 3 m/s2, the applied force can be calculated as:

Force = Mass × Acceleration
Force = 1,000 kg × 3 m/s2 = 3,000 N (newtons)
Force = 3,000 N

Conclusion

Understanding fundamental and derived quantities is important in the study of physics. Fundamental quantities are basic measurement blocks, while derived quantities extend these building blocks to describe more complex phenomena. By learning these concepts, one can explore various physical situations with accuracy and depth.

As you continue to explore physics, try to identify whether the things you measure are fundamental or derived. When you read the speed of your bicycle, calculate the energy from a moving object, or estimate the area of your room, remember these concepts and consider how they are interconnected. This foundation will help you delve deeper into more complex scientific studies.


Grade 7 → 2.1


U
username
0%
completed in Grade 7

← Prev (2)
Measurement and units
Next (2.2) →
SI units and unit conversions

Comments 



Fundamental and derived quantities

https://www.physicsflow.com/g7/2.1?pfal=en