27. The fundamental SI unit of length is the meter. How- ever, we often deal with larger or smaller lengths or

distances for which multiples or fractions of the fun-

damental unit are more useful. For each of the fol-

lowing situations, suggest what fraction or multiple

of the meter might be the most appropriate mea-

surement.

a. the distance between Chicago and Saint Louis

b. the size of your bedroom

c. the dimensions of this textbook

d. the thickness of a hair

A) Km

B) m

C) cm

D) mm

Explanation:

A) The distance between Chicago and Saint Louis is quite a distance and would be best presented in the largest multiple of the SI unit of length.

For example if the distance is 500000 m, it's a bit bogus to write, so we can simplify by writing in terms of 10^(-3) m which is in km.

Thus, we can write as 500000 × 10^(-3) km = 500 km

B) By standard measurement, the size of a bedroom is usually: 3.6 m × 3.6 m.

This not complex to write and can be kept as it is in metres.

C) The average dimension of a textbook is around 0.25 m by 0.2 m.

Let's get rid of the decimal by converting to terms of 10² m which is expressed as cm.

Thus, dimension is now: (0.25 × 10²) by (0.2 × 10²) = 25 cm by 20 cm

D) Average thickness of a hair in metres is 8 × 10^(-5) m.

Now this is a bit long. So we can express is in terms of 10^(3) m which is an expression denoted by millimeter (mm).

Thus, thickness is 8 × 10^(-5) × 10³ = 0.08 mm

false

because it does not have the potential to be entirely used up