Overview
This lecture explains derived units in the metric system, including examples and how they relate to fundamental SI units.
Fundamentals of Derived Units
- Derived units are combinations of base SI (International System of Units) units.
- These units are formed by multiplying or dividing base units together.
Common Examples of Derived Units
- Area is measured in square meters (m²), calculated as length × width.
- Volume is measured in cubic meters (m³), calculated as length × width × height.
- Speed is measured in meters per second (m/s), calculated as distance ÷ time.
- Density is measured in kilograms per cubic meter (kg/m³), calculated as mass ÷ volume.
- Force is measured in newtons (N), defined as kilograms × meters per second squared (kg·m/s²).
- Pressure is measured in pascals (Pa), defined as newtons per square meter (N/m²).
- Energy is measured in joules (J), defined as newton-meters (N·m).
Key Terms & Definitions
- Derived Unit — a unit created by combining two or more base SI units.
- SI Units — base units in the International System of Units used for scientific measurement.
- Area (m²) — a measure of surface, found by multiplying two lengths.
- Volume (m³) — a measure of space, found by multiplying three lengths.
- Speed (m/s) — the rate of distance covered per unit time.
- Density (kg/m³) — mass per unit volume.
- Force (N) — the push or pull on an object, calculated as mass × acceleration.
- Pressure (Pa) — force applied per unit area.
- Energy (J) — the ability to do work.
Action Items / Next Steps
- Memorize common derived units and their relationships to base SI units.
- Practice converting between base units and derived units.