Multiple Choice
Which phrase best describes air pressure?
70
views
1. Intro to Physics Units
Introduction to Units
Multiple Choice
Which of the following is the basis of the current standard for the ?
A
The distance traveled by light in vacuum during a specific fraction of a
B
The length of a platinum-iridium bar kept in Paris
C
The wavelength of orange-red light emitted by (krypton-86)
D
The circumference of the Earth at the equator
Verified step by step guidance1
Understand that the problem asks about the basis of the current standard for the meter, which is a unit of length in the International System of Units (SI).
Recall that historically, the meter was defined by physical objects or natural phenomena, such as the length of a platinum-iridium bar or the wavelength of light emitted by krypton-86.
Recognize that modern definitions aim for greater precision and reproducibility, so the meter is now defined based on a fundamental constant of nature.
Know that the current standard defines the meter as the distance light travels in vacuum during a specific fraction of a second, linking the unit of length to the constant speed of light.
Therefore, the correct basis for the current meter standard is the distance traveled by light in vacuum during a defined time interval, ensuring high precision and universality.
Related Videos
Related Practice
