5 An object of mass m is observed to move in a straight line with velocity given by v=bt²-ct, where b and c are positive constants. The expression for the force on the object as a function of time is
(A)mbt²-mct
(B)2mbt²-2mct
(C)2mbt-mc
(D)mbt-mc
(E)mbt²-0.5mct

相關試題

相關試卷