<Tr> <Th> Pressure (p) </Th> <Td> lb / in </Td> <Td> at </Td> <Td> psi </Td> <Td> atm </Td> <Td> pdl / ft </Td> <Td> Ba </Td> <Td> pz </Td> <Td> Pa </Td> </Tr> <P> In the "engineering" systems (middle column), the weight of the mass unit (pound - mass) on Earth's surface is approximately equal to the force unit (pound - force). This is convenient because one pound mass exerts one pound force due to gravity . Note, however, unlike the other systems the force unit is not equal to the mass unit multiplied by the acceleration unit--the use of Newton's Second Law, F = m ⋅ a, requires another factor, g, usually taken to be 32.174049 lb ⋅ ft / lbf ⋅ s . "Absolute" systems are coherent systems of units: by using the slug as the unit of mass, the "gravitational" FPS system (left column) avoids the need for such a constant . The SI is an "absolute" metric system with kilogram and meter as base units . </P>

5 foot pounds equals how many inch pounds