Equation 2 · The Last Artefact: Redefining the Kilogram
What does this equation mean?
Read the formula alongside the article passage below. Each part has a deeper page with its role in the equation, the supporting passage and nearby citations.
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions. Read the equation part by part below; each part has a contextual explanation and a link to its mathematical background.
Read it piece by piece
Symbol m_x
is part of the quantity the equation computes from the expression on the right.
Symbol g
g is part of the quantity the equation computes from the expression on the right.
Symbol I_1
is an input to the expression that computes the quantity on the left.
Symbol B
B is an input to the expression that computes the quantity on the left.
Symbol l
l is an input to the expression that computes the quantity on the left.
Symbol U_2
is an input to the expression that computes the quantity on the left.
=
The expressions on both sides represent the same quantity under the stated assumptions.
See an illustrated explanation →subscript
The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.
How to interpret it
Read it with the definitions, units, and assumptions supplied by the article.
What the article says around this equation
The Kibble balance runs in two modes. In weighing mode, the weight of an artefact of mass m is balanced by the force on a coil of wire length l carrying current I₁ in a radial field of flux density B. In moving mode, the same coil is driven vertically at velocity v through the same field and the induced voltage U₂ is measured [ 4 ] : . The geometric factor Bl appears in both and is eliminated between them:
Sources cited in the surrounding passage
These citations give research context. Read each source to check which claims it supports.
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