Measurements and units
Our summary: The basic and derived units, measuring instruments, dimensions and how accurate a measurement can be.
Contents
- Fundamental unitsJAMB note: Length, mass, time, electric charge, temperature, luminous intensity, amount of substance.
- Derived unitsJAMB note: Weight, area, volume, force, speed etc.
- Measuring instrumentsJAMB note: Vernier caliper, metre rule, micrometer screw gauge, measuring cylinder, stop watch and beam balance.
- Fundamental physical quantities
- Derived physical quantities and their unitsJAMB note: Combinations of fundamental quantities and determination of their units.
- DimensionsJAMB note: (i) definition of dimensions; (ii) simple examples.
- Limitations of experimental measurementsJAMB note: (i) accuracy of measuring instruments; (ii) simple estimation of errors; (iii) significant figures; (iv) standard form.
Objectives
- identify the units of length, area and volume;
- use different measuring instruments;
- determine the lengths, surface areas and volume of regular and irregular bodies;
- identify the unit of mass;
- use simple beam balance, e.g. Buchart's balance and chemical balance;
- identify the unit of time;
- use different time-measuring devices;
- relate the fundamental physical quantities to their units;
- deduce the units of derived physical quantities;
- determine the dimensions of physical quantities;
- use the dimensions to determine the units of physical quantities;
- test the homogeneity of an equation;
- determine the accuracy of measuring instruments;
- estimate simple errors;
- express measurements in standard form.
