Units and Measurements Chapter 1 Quiz

Units and Measurements

• A unit is a quantity or amount used as a standard of measurement.
• Units consist of a numerical magnitude and a unit, represented as Q = Nu, where Q is the physical quantity, N is the number, and u is the unit.

Physical Quantities

• Physical quantities are quantities that can be measured.
• Examples of physical quantities include length, mass, time, and temperature.

Derived Quantities

• Derived quantities are quantities that are derived from physical quantities.
• Examples of derived quantities include area, volume, and velocity.

Basic and Derived Units

• The units of basic quantities are called basic units.
• The units of derived quantities are called derived units.

Systems of Units

• There are three systems of units: the British system, the Metric system, and the SI unit system.

The British System

• The British system is based on foot (ft), pound (lb), and second (s).
• It is also called the FPS system.

The Metric System

• The Metric system consists of two subsystems: the CGS system and the MKS system.
• The CGS system is based on centimeter (cm), gram (g), and second (s).
• The MKS system is based on meter (m), kilogram (kg), and second (s).

The SI Unit System

• The SI unit system is a modified form of the MKS system.
• It is the most widely used system of units.

Units of Length, Mass, and Time

• The unit of length is meter (m) in the MKS and SI systems, centimeter (cm) in the CGS system, and foot (ft) in the FPS system.
• The unit of mass is kilogram (kg) in the MKS and SI systems, gram (g) in the CGS system, and pound (lb) or slug (sl) in the FPS system.
• The unit of time is second (s) in all systems of measurement.