SI units Flashcards
(23 cards)
What are SI units?
Standardized units used globally in science, known as the Système Internationale d’Unités (SI units)
The exception is North America, which uses imperial units.
What are the seven base SI units?
- kilogram (kg)
- metre (m)
- second (s)
- ampere (A)
- kelvin (K)
- mole (mol)
- candela (cd)
These units provide a foundation for all other measurements in the SI system.
What is the SI unit for mass?
kilogram (kg)
Mass is the amount of matter in an object.
What is the SI unit for time?
second (s)
Time is a fundamental measurement in various scientific calculations.
What is the SI unit for length?
metre (m)
Length is used to measure distance.
What is the difference between mass and weight?
Mass is measured in kilograms; weight is a force measured in newtons (N).
Weight is calculated as force × acceleration due to gravity.
How is pressure defined?
Pressure is defined as force/area
The SI unit for pressure is pascal (Pa), where 1 Pa = 1 N/m².
What is the SI unit for pressure?
pascal (Pa)
1 pascal is equivalent to 1 newton per square metre.
What is the formula for calculating pressure?
Pressure = force/area
Force is measured in newtons and area in square metres.
What is the SI unit for volume?
cubic metre (m³)
One litre equals 0.001 m³.
What is the SI unit for force?
newton (N)
1 N = 1 kg·m/s².
What is a derived unit?
A unit that is derived from the seven base SI units
Examples include newton (N) and pascal (Pa).
What unit measures electric potential?
volt (V)
Voltage is a derived unit in the SI system.
What is the SI unit for power?
watt (W)
This unit measures the rate of energy transfer.
What does the prefix ‘kilo-‘ represent?
10³
It is used to denote a factor of one thousand.
Convert 1 megawatt to watts.
1 MW = 1,000,000 W
Mega- denotes a factor of one million.
What is the SI unit for density?
kg/m³
Density is mass per unit volume.
Fill in the blank: The SI unit for energy is _______.
joule (J)
Energy is the capacity to do work.
True or False: 1 inch is equal to 0.0254 metres.
True
This is a standard conversion for length.
What is the conversion from metres to feet?
1 ft = 0.3048 m
This is useful for converting between metric and imperial systems.
What is engineering notation?
A form where the exponent of 10 is divisible by 3
It simplifies the representation of large or small numbers.
What is the SI unit for luminous intensity?
candela (cd)
This unit measures the perceived power of light.
What is the SI unit for temperature?
kelvin (K)
This unit is used in scientific contexts to measure thermal energy.
