( ( ( This combination ) ( of forces ) ) ( ( is ( ( ( linearly ( proportional ( to ( the ( absolute temperature ) ) ) ) ) and ) ( inversely ( proportional ( to ( ( the volume ) ( -LRB- ( 2 -RRB- ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT This) (NN combination)) (PP (IN of) (NP (NNS forces)))) (VP (VBZ is) (UCP (ADJP (RB linearly) (JJ proportional) (PP (TO to) (NP (DT the) (JJ absolute) (NN temperature)))) (CC and) (VP (ADVP (RB inversely)) (VBN proportional) (PP (TO to) (NP (NP (DT the) (NN volume)) (PRN (-LRB- -LRB-) (NP (CD 2)) (-RRB- -RRB-))))))) (. .)))
This combination of forces is linearly proportional to the absolute temperature and inversely proportional to the volume (2).
(ROOT (S (NP (NNS Experiments)) (VP (VBP have) (VP (VBN shown) (SBAR (IN that) (S (NP (NN acceleration)) (VP (VBZ is) (ADVP (RB exactly)) (ADVP (RB inversely) (NP (CD proportional)) (PP (TO to) (NP (NN mass)))) (, ,) (SBAR (RB just) (IN as) (S (NP (PRP it)) (VP (VBZ is) (ADVP (RB exactly)) (ADJP (RB linearly) (JJ proportional) (PP (TO to) (NP (DT the) (JJ net) (JJ external) (NN force)))))))))))) (. .)))