The meter is presently defined as
a. one ten-millionth of the diameter of Earth.
b. the wavelength of a line in the spectrum of krypton-86.
c. the length of a platinum-iridium bar.
d. the distance light travels in a vacuum in a very short time.
Question 2
The meter was defined originally as
a. one ten-millionth of the diameter of Earth.
b. one ten-millionth of the distance from the equator to the North Pole.
c. the wavelength of a line in the spectrum of krypton-86.
d. the length of a platinum-iridium bar.