Physics Kenya
Measurements I
Measurements I
Measurements I
Measurement is the process of assigning numbers to observations or events. It is the process in which the amount of values, data or quantity is obtained. Measurement is an important activity in Physics. During measurement, a scientist follows proper procedures and uses proper instruments so as to get exact amounts.
Definition of length, area, volume, mass, density and time
SI units and symbols
SI unit (International system of units): Is the system of units which is used internationally to measure seven basic physical quantities.
| Fundamental quantity | SI unit | Unit symbol | Other common units |
| Mass | Kilogram | kg | Tones (t), gram (g) |
| Length | Metre | m | Kilometre (km), centimetre (cm), millimetre (mm) |
| Time | Second | s | Hours (hr), minutes (min) |
| Temperature | Kelvin | K | Centigrade degrees (), Fahrenheit degrees () |
| Luminous intensity | Candela | cd | Candle power |
| Amount of substance | Mole | mol | Pound mole (lb-mol) |
| Electric current | Ampere | A | No other units |
- Giga(G) = 1,000,000,000 (10ˆ9)
- Mega(M) = 1,000,000 (10ˆ6)
- Kilo(K) = 1,000(10ˆ3)
- Hector (h) = 100(10ˆ2)
- Decca(da) = 10(10ˆ1)1
- Deci (d) = 1/10 (10ˆ-1)
- Cent (c) = 1/100(10ˆ-2)
- Mill (m) = 1/1000 (10ˆ-3)
- Micro(μ) = 1/1,000,000(10ˆ-6)
Estimation of quantities
Conversion of units
Measuring instruments
Experiments on density
Problems on density
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