Question

things we measure

length

Answer 1

Here are common kinds of quantities we measure, with typical units and instruments (short list):

SI base quantities (fundamental)
- Length — meter (m). Tools: ruler, tape measure, caliper, laser distance meter.
- Mass — kilogram (kg). Tools: balance, scale.
- Time — second (s). Tools: stopwatch, clock, timer.
- Electric current — ampere (A). Tools: ammeter, multimeter.
- Thermodynamic temperature — kelvin (K) (often °C in everyday use). Tools: thermometer, thermocouple.
- Amount of substance — mole (mol). Tools: calculated from mass/volume and concentration measurements.
- Luminous intensity — candela (cd). Tools: photometer, light meter.

Common derived or practical quantities
- Area — square meter (m²). Tools: planimeter, measuring tape + calculation.
- Volume — cubic meter (m³), liter (L). Tools: measuring cup, graduated cylinder, flow meters.
- Speed / velocity — m/s. Tools: radar gun, speedometer, timing over distance.
- Acceleration — m/s². Tools: accelerometer, motion sensors.
- Force — newton (N). Tools: force gauge, load cell.
- Pressure — pascal (Pa), bar. Tools: pressure gauge, manometer.
- Energy / work — joule (J). Tools: calorimeter (for heat), electrical measurements.
- Power — watt (W). Tools: wattmeter, power meter.
- Frequency — hertz (Hz). Tools: frequency counter, oscilloscope.
- Electric potential (voltage) — volt (V). Tools: voltmeter, multimeter.
- Resistance — ohm (Ω). Tools: ohmmeter, multimeter.
- Charge — coulomb (C). Tools: electrometers.
- Magnetic field — tesla (T). Tools: gaussmeter.
- Humidity — % relative humidity. Tools: hygrometer.
- pH (acidity) — pH units. Tools: pH meter, indicator paper.
- Sound level — decibel (dB). Tools: sound level meter.
- Light intensity / illuminance — lux (lx). Tools: lux meter.
- Density — kg/m³. Tools: mass and volume measurements.
- Concentration (chemistry) — mol/L, ppm. Tools: spectrophotometer, titration.
- Angle — degrees (°), radians. Tools: protractor, inclinometer.

If you want, I can:
- Expand any item with examples and how to measure it,
- Provide a printable list for classroom use,
- Give lab-safe methods or tools for a particular setting. Which would you like?