1.2.1 Base quantities Prefixes
Prefixes are the preceding factor used to represent very
small and very large physical quantities in SI units.
Physical Quantities
1. A physical quantity is a quantity that can be measured.
2. A physical quantity can be divided into base quantity and derived quantity.
Base Quantities
1. Base quantities are the quantities that are conventionally
accepted as functionally independent of one another.
2.It is a quantity that cannot be defined in term of other physical quantity. 1.3 Scalar and Vector quantities
3.The base quantities and its units are as in the table below:
Scalar Quantities | Vector Quantities |
Speed | Density | Velocity |
Distance | Length | Acceleration |
Energy | Time | Displacement |
Electric Charge | Temperature | Momentum |
Volume | Mass | Force |
Examples:
1.4 Consistency, accuracy and sensitivity
Precision
1. Precision is the ability of an instrument in measuring a quantity in a consistent manner with only a small relative deviation between readings.
2. The precision of a reading can be indicated by its relative deviation.
3. The relative deviation is the percentage of mean deviation for a set of measurements and it is defined by the following formula:
Accuracy
1. The accuracy of a measurement is the approximation of the measurement to the actual value for a certain quantity of Physics.
2. The measurement is more accurate if its number of significant figures increases
3. Table above shows that the micrometer screw gauge is more accurate than the other measuring instruments.
4. The accuracy of a measurement can be increased...