( ( ( The motion ) ( of ( ( the charge ) ( on ( the belt ) ) ) ) ) ( ( ( is ( in ( ( a ( direction opposite ) ) ( to ( the force ) ) ) ) ) ( that ( ( ( the ( electric field ) ) ( of ( the dome ) ) ) ( exerts ( on ( the charge ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN motion)) (PP (IN of) (NP (NP (DT the) (NN charge)) (PP (IN on) (NP (DT the) (NN belt)))))) (VP (VBZ is) (PP (IN in) (NP (NP (DT a) (NN direction) (NN opposite)) (PP (TO to) (NP (DT the) (NN force))))) (SBAR (IN that) (S (NP (NP (DT the) (JJ electric) (NN field)) (PP (IN of) (NP (DT the) (NN dome)))) (VP (VBZ exerts) (PP (IN on) (NP (DT the) (NN charge))))))) (. .)))
The motion of the charge on the belt is in a direction opposite to the force that the electric field of the dome exerts on the charge.
(ROOT (S (NP (NNP Work)) (VP (VBZ is) (VP (VBN done) (SBAR (RB only) (IN if) (S (NP (DT a) (NN force)) (VP (VBZ is) (VP (VBN exerted) (PP (IN in) (NP (NP (DT the) (NN direction)) (PP (IN of) (NP (NN motion))))))))))) (. .)))