Zusammenfassung der Ressource
Physics:
Measurement
- Quantities
- Basic quantities
- Definition: A physical quantity that cannot be defined
in terms of other physical quantities.
- Length (m)
- Time (s)
- Mass (kg)
- Temperature (K)
- Luminous Intensity (cd)
- Amount of substance (mol)
- Electric Current (A)
- Derived Quantities
- Definition: A physical quantity that is derived from basic
quantities. (no standard definition)
- Density (p, rho) = mass/volume
- Momentum = mass x velocity
- Force (N) = mass x acceleration
- Pressure (Pa) = force/area
- Work done (J) = force/displacement
- Power (W) = work done/time
- Uncertainty
- Is the extent of precision of the measurements taken
with the intrument.
- Determined according to the smallest
division/graduation on the instrument's scale (in
other words, its precision).
- Measuring instruments, their smallest
division and their uncertainty
- Meter rule - 0.1 cm
Uncertainty: +/- 0.1 cm
- Vernier Caliper (20 division) - 0.05 cm
Uncertainty: +/- 0.01 cm
- Vernier Caliper (10 division) - 0.01 cm
Uncertainty: +/- 0.02 cm
- Micrometer Screw Gauge - 0.01 mm
Uncertainty: +/- 0.01 mm
- Thermometer - 0.5 °C
Uncertainty: +/- 03°C (for temperature reading) &
+/- 0.5°C (for temperature change)
- Stopwatch - 0.01 s
Uncertainty: +/- 0.02 s
- Electronic Mass Balance - 0.01 g
Uncertainty: +/- 0.01 g