( Pressure ( ( is ( defined ( as ( ( the amount ) ( of ( force ( per ( unit area ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NN Pressure)) (VP (VBZ is) (VP (VBN defined) (PP (IN as) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN force)) (PP (IN per) (NP (NN unit) (NN area))))))))) (. .)))
Pressure is defined as the amount of force per unit area.
(ROOT (S (NP (NN Pressure)) (VP (VBZ is) (VP (VBN defined) (PP (IN in) (NP (NN physics))) (PP (IN as) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN force)) (VP (VBG pushing) (PP (IN against) (NP (DT a) (VBN given) (NN area)))))))))) (. .)))