Page 273 - ABCTE Study Guide_Neat

Question

Which of the following lengths is greatest?

A 7 in

B
ft

C 15 cm

D 125 mm

Answer

Choice A is the correct answer. Fifteen cm is about six in.; 125 mm equals 12.5 cm, which is about 5

inches; and ft equals 6 in. Of the measures given, seven in. is the greatest.

Combining Units

The basic units given in each of the systems above are called simple units. Simple units can be put
together to derive units of measurement for other quantities. Naturally, these put-together units are
called derived units.

This may sound more complicated than it is. Miles per hour is a derived unit. So are square meters, hours
per week, people-hours, and kilogram-meters per second squared. (See, some are more derived than
others.) In fact, a kilogram-meter per second squared is called a Newton, so a Newton is also a derived
unit, even though it looks simple.

Question

Rate is equal to the quotient of distance and time, or . Which of the following is a unit of rate?

A hours per week

B inches per foot

C miles per gallon

D meters per second