chapter 1

• what are the 7 base quantities?

  length, mass, time, thermodynamic temperature, electric current, amount of substance, luminous intensity
• what is the SI unit and symbol for length?

  metre, m
• what is the SI unit and symbol for mass?

  kilogram, kg
• what is the SI unit and symbol for time

  second, s
• what is the SI unit and symbol for electric current?

  ampere, A
• what is the SI unit and symbol for thermodynamic temperature?

  kelvin, K
• what is the SI unit and symbol for amount of substance?

  mole, mol
• what is the symbol and factor for the prefix tera?

  10^12, T
• what is the symbol and factor for the prefix giga?

  10^9, G
• what is the symbol and factor for the prefix mega?

  10^6, M
• what is the symbol and factor for the prefix kilo?

  10^3, k
• what is the symbol and factor for the prefix deci?

  10^-1, d
• what is the symbol and factor for the prefix centi?

  10^-2, c
• what is the symbol and factor for the prefix milli?

  10^-3, m
• what is the symbol and factor for the prefix micro?

  10^-6, weird u shape
• what is the symbol and factor for the prefix nano?

  10^-9, n
• metre rule


  can measure length from zero up to 1metre

  smallest division is 0.1cm or 1mm

  can be used to measure the height of a table
• digital caliper

  can measure length from zero up to 15cm

  smallest division is 0.001cm or 0.01mm

  can be used to measure the internal and external diameters of an object
• digital micrometer of screw gauge

  can measure length from zero up to 2.5cm

  smallest division is 0.0001cm or 0.001mm

  can be used to measure objects that are too small to be measured using the digital calipers
• measuring tape


  can measure length from zero up to several metres

  smallest division is 0.1cm or 1mm

  can be used to measure a person's waist
• avoiding parallax error

  eyes should be positioned such that our line of sight id perpendicular to or directly above the metre rule
• avoiding zero error

  wear and tear of the metre rule can make the worn end unsuitable for reading, introducing errors to the readings

  measure from another point and subtract it from the final reading
• pendulum

  every one complete to and fro motion is one oscillation

  the period of the pendulum is the time taken for one complete oscillation
• human reaction time

  stopwatches need to be start and stopped by hand

  this manual operation introduces a random error known as human reaction error

  thus although a digital stopwatch shows a reading of up to 2 decimal places, we usually take readings to the nearest 1 decimal place