Understanding the Kilogram and Its Redefinition

The video discusses the kilogram, the basic unit of mass in the metric system, and its historical development. It highlights issues with the current prototype kilogram, which is losing reliability due to mass drift. Scientists aim to redefine the kilogram using the Planck constant, similar to other base units. This involves using a watt balance to measure mass in terms of universal constants, eliminating the need for physical prototypes. The BIPM plans to finalize this redefinition by 2018, ensuring more accurate and reliable mass measurements.

What is the basic unit of mass in the metric system?

• Ounce

• Pound

• Kilogram

• Gram

Which event led to the proposal of a new unit of mass based on water?

• World War I

• The American Revolution

• The Industrial Revolution

• The French Revolution

What material was used to create the prototype kilogram?

• Copper

• Silver

• Gold

• Iridium-Platinum Alloy

Where is the prototype kilogram stored?

• New York

• London

• Berlin

• Paris

What problem was discovered with the prototype kilogram about 30 years ago?

• It was corroding

• It was stolen

• Its mass was changing

• It was melting

What is the proposed solution to redefine the kilogram?

• Using a larger prototype

• Using universal constants

• Using a digital scale

• Using a new metal

Which constant is being considered to redefine the kilogram?

• Gravitational constant

• Planck constant

• Avogadro's number

• Boltzmann constant

What device is used to measure the kilogram in terms of the Planck constant?

• Digital scale

• Watt balance

• Triple beam balance

• Spring scale

When does the BIPM plan to make the new definition of the kilogram official?

• 2015

• 2022

• 2018

• 2020

What will the new definition of the kilogram be based on?

• Energy of photons

• Weight of water

• Distance light travels

• Mass of a specific object