Question Number 20936 by Tinkutara last updated on 08/Sep/17
$$\mathrm{A}\:\mathrm{graph}\:\mathrm{of}\:{x}\:\mathrm{versus}\:{t}\:\mathrm{is}\:\mathrm{shown}\:\mathrm{in}\:\mathrm{Figure}. \\ $$ $$\mathrm{Choose}\:\mathrm{correct}\:\mathrm{alternatives}\:\mathrm{from}\:\mathrm{below}. \\ $$ $$\left({a}\right)\:\mathrm{The}\:\mathrm{particle}\:\mathrm{was}\:\mathrm{released}\:\mathrm{from} \\ $$ $$\mathrm{rest}\:\mathrm{at}\:{t}\:=\:\mathrm{0} \\ $$ $$\left({b}\right)\:\mathrm{At}\:{B},\:\mathrm{the}\:\mathrm{acceleration}\:{a}\:>\:\mathrm{0} \\ $$ $$\left({c}\right)\:\mathrm{At}\:{C},\:\mathrm{the}\:\mathrm{velocity}\:\mathrm{and}\:\mathrm{the} \\ $$ $$\mathrm{acceleration}\:\mathrm{vanish} \\ $$ $$\left({d}\right)\:\mathrm{Average}\:\mathrm{velocity}\:\mathrm{for}\:\mathrm{the}\:\mathrm{motion} \\ $$ $$\mathrm{between}\:{A}\:\mathrm{and}\:{D}\:\mathrm{is}\:\mathrm{positive} \\ $$ $$\left({e}\right)\:\mathrm{The}\:\mathrm{speed}\:\mathrm{at}\:{D}\:\mathrm{exceeds}\:\mathrm{that}\:\mathrm{at}\:{E}. \\ $$
Commented byTinkutara last updated on 08/Sep/17
Answered by ajfour last updated on 09/Sep/17
$$\left({a}\right),\:\left({c}\right),\:\left({e}\right) \\ $$
Commented byTinkutara last updated on 09/Sep/17
$$\mathrm{Thank}\:\mathrm{you}\:\mathrm{very}\:\mathrm{much}\:\mathrm{Sir}! \\ $$
Commented byajfour last updated on 09/Sep/17
$${if}\:{the}\:{graph}\:{of}\:{x}-{t}\:{changes}\:{from} \\ $$ $${convex}\:{to}\:{concave}\:{or}\:{vice}-{versa} \\ $$ $${acceleration}\:{is}\:{zero}\:{there},\:{and} \\ $$ $${if}\:{tangent}\:{to}\:{it}\:{is}\:{hrizontal}\:{then} \\ $$ $${velocity}\:{is}\:{zero}.\:{At}\:{C}\:{both}\:{the} \\ $$ $${conditions}\:{seem}\:{fulfilled}.\:{Speed}\:{or} \\ $$ $${magnitude}\:{of}\:{slope}\left({velocity}\right)\:\:{at}\:{D}\: \\ $$ $${is}\:{more}\:{than}\:{at}\:{E}. \\ $$