Question Number 39750 by rahul 19 last updated on 10/Jul/18
Commented by rahul 19 last updated on 10/Jul/18
Commented by rahul 19 last updated on 10/Jul/18
$$\mathrm{Also}\:\mathrm{find}\:\mathrm{Acc}^{\mathrm{n}} \:\mathrm{of}\:\mathrm{block}\:\mathrm{A}\:\&\:\mathrm{D}\:\:\mathrm{just}\:\mathrm{after}\:\mathrm{the} \\ $$$$\mathrm{spring}\:\mathrm{1}\:\mathrm{is}\:\mathrm{cut}\:. \\ $$
Commented by rahul 19 last updated on 10/Jul/18
$$\mathrm{Mrw}\:\mathrm{Sir}\:,\:\mathrm{this}\:\mathrm{Q}.\:\mathrm{is}\:\mathrm{waiting}\:\mathrm{for}\:\mathrm{u}\:. \\ $$
Answered by MrW3 last updated on 11/Jul/18
$${With}\:``{after}\:{the}\:{cut}\:{of}\:{a}\:{string}''\:{I}\:{don}'{t}\:{mean} \\ $$$${the}\:{instant}\:{when}\:{the}\:{string}\:{is}\:{cut}. \\ $$$$ \\ $$$${Before}\:{a}\:{string}\:{is}\:{cut}: \\ $$$${T}_{{AB}} =\mathrm{30}\:{N} \\ $$$${T}_{{S}\mathrm{1}} =\mathrm{60}\:{N} \\ $$$${T}_{{S}\mathrm{2}} =\mathrm{20}\:{N} \\ $$$${T}_{{CD}} =\mathrm{40}\:{N} \\ $$$${T}_{{CP}} =\mathrm{60}\:{N} \\ $$$${After}\:{cut}\:{at}\:{spring}\:\mathrm{2}: \\ $$$${a}=\frac{\left(\mathrm{6}−\mathrm{4}\right){g}}{\mathrm{6}+\mathrm{4}}=\frac{{g}}{\mathrm{5}}=\mathrm{2}\:{m}/{s}^{\mathrm{2}} \\ $$$$\mathrm{30}−{T}_{{AB}} =\mathrm{3}×\mathrm{2} \\ $$$$\Rightarrow{T}_{{AB}} =\mathrm{24}\:{N}<\mathrm{30}\:{N} \\ $$$$\Rightarrow{Q}\left({i}\right)\Rightarrow{A}\left({b}\right) \\ $$$$ \\ $$$${T}_{{CD}} −\mathrm{20}=\mathrm{2}×\mathrm{2} \\ $$$$\Rightarrow{T}_{{CD}} =\mathrm{24}\:{N}<\mathrm{40}\:{N} \\ $$$$\Rightarrow{Q}\left({ii}\right)\Rightarrow{A}\left({b}\right) \\ $$$$ \\ $$$${After}\:{cut}\:{at}\:{string}\:{btw}.\:{C}\:{and}\:{pulley}: \\ $$$${A}\:{and}\:{B}\:{have}\:{frei}\:{fall}. \\ $$$${C},{D}\:{and}\:{E}\:{have}\:{frei}\:{fall}. \\ $$$${T}_{{AB}} =\mathrm{0} \\ $$$${T}_{{CD}} =\mathrm{0} \\ $$$$\Rightarrow{Q}\left({iii}\right)\Rightarrow{A}\left({d}\right) \\ $$$$ \\ $$$$\Rightarrow{Q}\left({iv}\right)\Rightarrow{A}\left({d}\right) \\ $$
Commented by rahul 19 last updated on 13/Jul/18
Sorry sir , your ans. didn't match with book ans. Kindly check !
Commented by rahul 19 last updated on 13/Jul/18
$$\mathrm{Ans}. \\ $$$$\left(\mathrm{i}\right)\:\rightarrow\:\mathrm{c} \\ $$$$\left(\mathrm{ii}\right)\rightarrow\mathrm{b} \\ $$$$\left(\mathrm{iii}\right)\rightarrow\mathrm{b},\mathrm{d} \\ $$$$\left(\mathrm{iv}\right)\rightarrow\mathrm{b}. \\ $$
Commented by MrW3 last updated on 13/Jul/18
$${I}\:{know}.\:{The}\:{answer}\:{depents}\:{very}\:{much} \\ $$$${what}\:{is}\:{meant}\:{with}\:``{after}\:...''.\:\:{For} \\ $$$${my}\:{answers}\:{I}\:{didn}'{t}\:{mean}\:{the}\:{instant} \\ $$$${immediately}\:{after}\:{a}\:{string}\:{is}\:{cut},\:{but} \\ $$$${I}\:{meant}\:{the}\:{stable}\:{state}\:{after}\:{a}\:{string} \\ $$$${is}\:{cut}.\:{In}\:{this}\:{state}\:{all}\:{objects}\:{have}\:{a} \\ $$$${defined}\:{motion}. \\ $$$${Please}\:{don}'{t}\:{take}\:{this}\:{kind}\:{of}\:{solution} \\ $$$${from}\:{me}\:{as}\:``{correct}''\:{solution}. \\ $$
Commented by rahul 19 last updated on 13/Jul/18
$$\left.\mathrm{Ok}\:,\:\mathrm{Thank}\:\mathrm{You}\:\mathrm{Sir}\::−\right) \\ $$
Answered by MrW3 last updated on 11/Jul/18
$${At}\:{the}\:{moment}\:{just}\:{after}\:{the}\:{spring}\:\mathrm{1} \\ $$$${is}\:{cut}: \\ $$$$\mathrm{3}×\mathrm{10}−\mathrm{30}=\mathrm{3}{a}_{{A}} \\ $$$$\Rightarrow{a}_{{A}} =\mathrm{0} \\ $$$${similarly} \\ $$$$\Rightarrow{a}_{{D}} =\mathrm{0} \\ $$