Overview
The lecture covers the basics of measurement, including definitions, common physical quantities, units (metric and imperial), and practical methods for converting between units.
What is Measurement?
- Measurement is the process of finding the amount of a physical quantity by measuring it.
- Physical quantities include length, area, mass, volume/capacity, time, and temperature.
Common Physical Quantities & Units
- Length: metric (millimeter, centimeter, meter, kilometer); imperial (inch, foot, yard, mile).
- Area: amount of two-dimensional space, units are squared (mm², cm², m², km²).
- Mass: amount of matter; metric (milligram, gram, kilogram); imperial (ounce, pound, ton).
- Volume/Capacity: space a 3D shape takes up or how much a container holds; metric (milliliter, liter, kiloliter), imperial (pint, quart, gallon), and cubic units for volume (cm³, m³).
- Time: units include seconds, minutes, hours, days, weeks, months, years, decades, centuries, millennia.
- Temperature: measured in degrees Celsius (°C) or Fahrenheit (°F).
Converting Units
- To convert length: multiply by 10, 100, or 1,000 when moving from larger to smaller units; divide when moving from smaller to larger.
- To convert mass: multiply or divide by 1,000 between milligrams, grams, kilograms, and tons.
- To convert capacity/volume: multiply/divide by 1,000 between milliliters, liters, and kiloliters; for cubic units, use powers of 10 or 100 appropriate to the change in dimensions.
- 1 milliliter = 1 cm³; 1 kiloliter = 1 m³.
- To convert time: multiply to go from larger to smaller units, divide for the reverse (e.g., 60 seconds = 1 minute).
- To convert temperature: °F = (1.8 × °C) + 32; °C = (°F – 32) ÷ 1.8.
Key Terms & Definitions
- Measurement — finding the amount of a physical quantity.
- Physical quantity — measurable attribute (length, area, mass, etc.).
- Area — amount of two-dimensional space, measured in squared units.
- Volume/Capacity — amount of 3D space, measured in cubic units or liters.
- Conversion — changing a measurement from one unit to another.
Action Items / Next Steps
- Practice converting units for each physical quantity.
- Memorize key formulas for temperature conversion.
- Review differences between metric and imperial units.