This is Part 2 of "Build Your Own Watt Balance". This video shows how the watt balance experiment can be used to determine h (also called Planck constant) or mass, depending on how you run the experiment.
The Lego watt balance is called NIST 5L, and was built as demonstration and teaching tool. The NIST 4 watt balance is part of the group of experiments determining a fixed value for h, which is crucial to the redefinition of the kilogram in 2018.
The video "Part 1: This is not a toy" is available here: vimeo.com/128598681/
Thank you to the researchers at:
Jon R. Pratt
Filmmaker: Amy Young; Science advisor: Michael Trott
This is a "pre-take" for the documentary film "The State of the Unit: The Kilogram", brought to you by the filmmaker with support from the Kickstarter Backers. For details about the forthcoming documentary, see stateoftheunit.com.