PhysicsUnits and MeasurementsLengthTimeMass

rifkee1011@gmail.com

Mass (Kilogram)

Electric Current (Ampere)

Time (Second)

Temperature (Kelvin)

Ammount of Substance (mol)

Length (Metre)

Luminous Intensity (Candela)

BasicQuantities

Unit Symbol Number of seconds (minutes or hours)

day d 86 400 s (1440 min, 24 hours)

hour h 3600 s

minute min 60 s

second s 1 s

millisecond ms 0.001 s

Unit Symbol Number of metre

kilometre km 1000 m

metre m 1 m

centimetre cm 0.01 m

millimetre mm 0.001 m

mikrometre µm 0.000 001 m

nanometre nm 0.000 000 001 m

Mass (kg) Length (metre) Time (second)

Three Basic Units of SI Units (le Système international d'unités )

• Mass (kilogram)

• Length (metre)• Time (second)

Unit Symbol Number of kilograms

Megatonne Mt 1 000 000 000 kg

tonne t 1 000 kg

kilogram kg 1 kg

gram g 0.001 kg

milligram mg 0.000001 kg

The metric prefixes

The Power of Ten Shorthand

The Standard Notation

• 5 = 5 x 1

• 50 = 5 x 101

• 500 = 5 x 102

• 5 000 000 = 5 x 106

• 0.05 = 5 x 10-2

• 0.0000005 = 5 x 10-7

• The speed of light = 300 000 km/s

= 3 x 105 km/s

• The diameter of bacteria= 0.002 µm

= 2 x 10-3 µm

= 0.000000002 m

= 2 x 10-9 m

Exercises

1. How many millimeters are there in:a) 1 cm b) 4 cm c) 0.5 cm d) 6.7 cm e) 1 m

2. What are these length in meter?a) 300 cm b) 550 cm c) 870 cm d) 43 cm e) 100 mm

3. Write the following as powers of ten with one figure before the decimal point:a) 100 000 b) 3500 c) 428 000 000 d) 504 e) 27

0564. Write the following in full:

a) 103 b) 2 x 106 c) 6.9 x 104 d) 1.34 x 102 e) 2.12 x 105

5. Write these fractions as power of ten:a) 1/1000 b) 7/1000 000 c) 21/100 000