Convert Pound-force Square Second/Foot (lbf·s²/ft) to Quarter (UK) (qr (UK)) instantly.
About these units
Pound-force Square Second/Foot (lbf·s²/ft)
This unit is part of the British Gravitational System, where mass is defined from force rather than the other way around. It can be interpreted as an inertial mass unit, since applying 1 pound-force to it would produce an acceleration of 1 foot per second squared. Historically, before the SI system clarified the distinction between force and mass, engineering fields often used mixed systems where pounds could represent either force (lbf) or mass (lbm). The unit lbf·s²/ft was introduced to straighten out these ambiguities in dynamic calculations such as impact forces, mechanical oscillations, and safety load computations. Today, the unit survives mostly in engineering textbooks, legacy calculations, and historical documentation. It demonstrates how complex and inconsistent measurement systems once were, and why global scientific communities moved toward SI clarity.
Quarter (UK) (qr (UK))
The UK quarter, equal to 28 pounds, corresponds to 1/4 of a UK hundredweight. Historically used in grain trade, wool markets, and taxation, it reflects the older English approach to structuring weights around the stone. Its direct link to the long hundredweight made it easy for merchants to calculate loads and price goods. While obsolete today, the UK quarter remains important for historians reconstructing traditional British commerce and agricultural economies.