2.1.1 SI Units

• What physical quantity does the metre measure in the SI system?

  Length
• What is the SI unit for time?

  Second
• What physical quantity does the mole measure in the SI system?

  Amount of substance
• What are derived units created from in the SI system?

  Base units
• What is the base unit composition of energy in joules (J)?

  kg, m, s
• Pressure is measured in pascals (Pa), which is force divided by area
• What is the conversion factor to convert kilograms to grams?

  1 kg = 1000 g
• What is the conversion factor for kilograms to grams?

  1 kg = 1000 g
• How many grams are in 3.5 kilograms?

  3500 grams
• Derived units are created by combining base units.


  True
• Velocity is measured in meters per second.

  True
• Steps for converting between units using conversion factors

  1️⃣ Identify the starting and target units

  2️⃣ Find the appropriate conversion factor

  3️⃣ Multiply the value by the conversion factor

  4️⃣ Simplify the units to get the final answer
• Conversion factors for SI units are powers of 10.
• What does the acronym SI stand for in the context of units?

  International System of Units
• The kilogram is the SI unit for mass.


  True
• What is the SI unit for thermodynamic temperature?

  Kelvin
• Place the following derived units in order of their increasing complexity:

  1️⃣ Velocity (m/s)

  2️⃣ Force (N)

  3️⃣ Energy (J)

  4️⃣ Power (W)
• The unit of force, the newton (N), is derived from mass and acceleration
• Frequency is measured in hertz (Hz), which is cycles per second.

  True
• 5 kilometers is equal to 5000 meters.


  True
• There are 60 seconds in a minute
• 1 kilogram is equal to 1000 grams.

  True
• Match the base SI unit with its physical quantity:

  metre (m) ↔️ length

  kilogram (kg) ↔️ mass

  second (s) ↔️ time

  ampere (A) ↔️ electric current
• The base SI unit for thermodynamic temperature is the kelvin.
• The prefix 'milli' has a multiplier of 10^-3.
• Who defines and maintains SI units?

  International standards bodies
• Which physical quantity does the ampere measure in the SI system?

  Electric current
• The candela is the SI unit for luminous intensity.


  True
• What is the formula for velocity in terms of base units?

  m/s
• What is the formula for power in terms of derived units?

  energy / time
• Match the SI prefix with its multiplier:

  kilo ↔️ 10^3

  mega ↔️ 10^6

  giga ↔️ 10^9

  milli ↔️ 10^-3
• How many centimeters are in a meter?

  100
• To convert between different units, use conversion factors that relate the two units.
• The SI system consists of 7 base units that define the fundamental physical quantities.
• What does the base SI unit 'kg' measure?

  mass
• What is the multiplier for the prefix 'kilo'?

  10^3
• 1 meter is equal to 1000 centimeters.

  False
• Non-SI units often have irregular conversion factors.


  True