If you are measuring the thickness of a strand of human hair, the most appropriate SI unit is the
A) kilometer.
B) meter.
C) centimeter.
D) millimeter.
E) micrometer.

Question

Quizplus · Accepted Answer

The thickness of a strand of human hair is very small, on the order of micrometers (µm). Therefore, the most appropriate SI unit to use would be the micrometer, which is 10^-6 meters. The other units listed (kilometer, meter, centimeter, millimeter) are much too large to be practical for measuring the thickness of a strand of human hair.

If You Are Measuring the Thickness of a Strand of Human