Dyne (dyn)
The dyne (dyn) is a force unit in the centimeter–gram–second (CGS) system. It was common in 19th and early 20th-century physics. One dyne equals 10⁻⁵ newtons. It is the force needed to accelerate a mass of one gram by one centimeter per second squared. Today, science uses the newton, but dynes are still used in specialized fields, such as measuring surface tension in chemistry and physics. The dyne helped bridge old metric units with today’s SI.
Pound-force (lbf)
The pound-force (lbf) is in the imperial system. It is the force gravity exerts on one pound of mass. Today, it is standardized to 4.44822 newtons. Pound-force has long been used in engineering, aviation, and the U.S. military. Despite the shift to metric, the pound-force (lbf) is still important in places that use imperial units. It is used in aerospace, engine performance, and mechanical testing. Its use demonstrates the enduring impact of imperial units.