( ( The principle ) ( ( is ( that ( ( ( the slope ) ( of ( ( the line ) ( on ( a ( position-time graph ) ) ) ) ) ) ( ( reveals ( useful information ) ) ( about ( ( the velocity ) ( of ( the object ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN principle)) (VP (VBZ is) (SBAR (IN that) (S (NP (NP (DT the) (NN slope)) (PP (IN of) (NP (NP (DT the) (NN line)) (PP (IN on) (NP (DT a) (JJ position-time) (NN graph)))))) (VP (VBZ reveals) (NP (JJ useful) (NN information)) (PP (IN about) (NP (NP (DT the) (NN velocity)) (PP (IN of) (NP (DT the) (NN object))))))))) (. .)))
The principle is that the slope of the line on a position-time graph reveals useful information about the velocity of the object.
(ROOT (S (PP (IN In) (NP (DT a) (JJ position-time) (NN graph))) (, ,) (NP (NP (DT the) (NN slope)) (PP (IN of) (NP (DT the) (NN line)))) (VP (VBZ represents) (NP (DT the) (NN velocity))) (. .)))
In a position-time graph, the slope of the line represents the velocity.