V1000

10-3

one-millionth

1/1,000,000

10-6

one-billionth

1/1,000,000,000

10-9

Astronomers measure factors such as size or distance using the metric system, a decimal system of weights and measures in which the kilogram (2.04 pounds), the meter (39.37 inches), and the liter (61.025 cubic inches) are the basic units of mass, length, and capacity, respectively. Names for the most common other units are formed by the addition of the following prefixes to these terms: kilo- (thousand), mega- (million), giga- (billion), centi- (1/ioo), milli- (1/iooo), and micro (7: ,ooo,ooo). So, for example, a kilometer is a thousand meters, while a millimeter is one-thousandth of a meter. Some astronomical measurements using the metric system are shown in Table 2-2.

Table 2-2: Distances

Units

Examples

1 centimeter (cm) = io mil

Thickness of pencil: 7 mm

limeters (mm) = o.394 inches

Diameter of golf ball: 4 cm

1 meter (m) = ioo cm =

Basketball player: 2 m

1,ooo mm = 39.4 inches =

Football field: 90 m

1.o9 yards

Was this article helpful?

0 0
Telescopes Mastery

Telescopes Mastery

Through this ebook, you are going to learn what you will need to know all about the telescopes that can provide a fun and rewarding hobby for you and your family!

Get My Free Ebook


Post a comment