Besaran dan Satuan

QUANTITIES AND UNITS

Quantities in physics are something that can be measured. Ex: length, width, volume, weight, etc. Units are something to indicate the smallest part of quantities.

Main quantities

Differencing quantities

X	1 mile	1 feet	1 inch	1 cm	1 km
1 mile	1				5280
1 feet		1	12
1 inch			1	2.54
1 cm				1
1 km					1

Daya

Usaha

Gaya

Energi

Kecepatan

Volume

Debit

Tekanan

Luas

Quantities

Units

Dimensions

Important Number

• All numbers except zero are important
• Zero number between non-zero numbers are important
• Zero number after decimal (in the right side of non-zero numbers) is an important numbers
• Zero number before decimal is an important numbers
• Important numbers was written until underlined numbers

Written expression of important numbers

1.24 cm = 0.0124 m (three important numbers)

0.0124 m à 1.24 × 10^-2 m

important numbers operation : à all operation must only have one un-expecting numbers

Measurements

Measuring by ordinary ruler (ordinary screw)

Smallest scale: 1 millimeter

Accuracy: Δx = x 1 mm = 0.5 mm= 0.05 cm

ex: measurement at 3.60 ~ 3.70 cm

result of measurement l = (x ± Δx) = (36.0 mm ± 0.5 mm) = (3.60 ± 0.05) cm

Measuring by millimeter ruler (millimeter screw)

Smallest scale: 0.1 millimeter

Accuracy: Δx =x 0.1 mm = 0.05 mm= 0.005 cm

10 scale nonius scale (vernier scale) = 9 mm

ex: measurement at 2.500 ~ 2.600 cm

     (vernier scale) nonius scale at the 4^th line

result of the measurement

 

Measuring by micrometer ruler (micrometer screw)

Smallest scale: 0.01 millimeter

Accuracy: Δx =x 0.0a1 mm = 0.005 mm= 0.0005 cm

50 scale nonius scale = 0.01 mm

ex: measurement at 2.500 ~ 2.600 mm

     (vernier scale) nonius scale at the 48^th line

result of the measurement