Question Number 23937 by ajfour last updated on 10/Nov/17 Commented by ajfour last updated on 10/Nov/17 $${A}\:{thin}\:{rod}\:{placed}\:{perpendicular} \\ $$$${on}\:{a}\:{rough}\:{horizontal}\:{surface} \\ $$$${and}\:{released}\:{at}\:{rest}.\:{Find}\:{angle} \\ $$$$\boldsymbol{\alpha}\:{at}\:{which}\:{its}\:{bottom}\:{end}\:{starts} \\ $$$${slipping}.\:{The}\:{coefficient}\:{of}…
Question Number 23932 by Tinkutara last updated on 10/Nov/17 $$\mathrm{A}\:\mathrm{cord}\:\mathrm{is}\:\mathrm{wound}\:\mathrm{around}\:\mathrm{the}\:\mathrm{circumference} \\ $$$$\mathrm{of}\:\mathrm{a}\:\mathrm{bicycle}\:\mathrm{wheel}\:\left(\mathrm{without}\:\mathrm{tyre}\right)\:\mathrm{of} \\ $$$$\mathrm{diameter}\:\mathrm{1}\:\mathrm{m}.\:\mathrm{A}\:\mathrm{mass}\:\mathrm{of}\:\mathrm{2}\:\mathrm{kg}\:\mathrm{is}\:\mathrm{tied}\:\mathrm{at} \\ $$$$\mathrm{the}\:\mathrm{end}\:\mathrm{of}\:\mathrm{the}\:\mathrm{cord}\:\mathrm{and}\:\mathrm{it}\:\mathrm{is}\:\mathrm{allowed}\:\mathrm{to} \\ $$$$\mathrm{fall}\:\mathrm{from}\:\mathrm{rest}.\:\mathrm{The}\:\mathrm{weight}\:\mathrm{falls}\:\mathrm{2}\:\mathrm{m}\:\mathrm{in}\:\mathrm{4} \\ $$$$\mathrm{s}.\:\mathrm{The}\:\mathrm{axle}\:\mathrm{of}\:\mathrm{the}\:\mathrm{wheel}\:\mathrm{is}\:\mathrm{horizontal} \\ $$$$\mathrm{and}\:\mathrm{the}\:\mathrm{wheel}\:\mathrm{rotates}\:\mathrm{with}\:\mathrm{its}\:\mathrm{plane} \\ $$$$\mathrm{vertical}.\:\mathrm{If}\:\mathrm{g}\:=\:\mathrm{10}\:\mathrm{ms}^{−\mathrm{2}} ,\:\mathrm{what}\:\mathrm{is}\:\mathrm{the}…
Question Number 23920 by ajfour last updated on 09/Nov/17 Commented by ajfour last updated on 09/Nov/17 $${Find}\:\boldsymbol{{u}},\:\boldsymbol{\theta}\:{for}\:{a}\:{projecile}\:{in}\:{terms} \\ $$$${of}\:\boldsymbol{{a}},\:\boldsymbol{{b}},\:{and}\:\boldsymbol{{R}}\:{such}\:{that}\:{it} \\ $$$${goes}\:{from}\:{A}\:{to}\:{B}\:{through}\:{M}\:, \\ $$$${the}\:{midpoint}\:{of}\:{upper}\:{edge}. \\ $$$${Assume}\:{the}\:{incline}\:{frictionless}.…
Question Number 89446 by I want to learn more last updated on 17/Apr/20 $$.. \\ $$ Commented by I want to learn more last updated…
Question Number 23897 by ajfour last updated on 09/Nov/17 Commented by ajfour last updated on 09/Nov/17 $$\:{The}\:{string}\:{is}\:{wrapped}\:{around} \\ $$$${the}\:{outer}\:{cicumference}\:{of}\:{spool} \\ $$$${of}\:{radius}\:\mathrm{2}{r}\:,\:{while}\:{it}\:{rolls}\:{on} \\ $$$${the}\:{track}\:{on}\:{its}\:{inner}\:{circle}\:{of} \\ $$$${radius}\:{r}.\:{Relate}\:\boldsymbol{{v}}\:{with}\:\boldsymbol{{u}}\:{in}\:{terms}…
Question Number 23891 by ketto last updated on 09/Nov/17 Commented by math solver last updated on 09/Nov/17 $$\mathrm{write}\:,\:\mathrm{0}.\mathrm{75}\:\mathrm{as}\:\frac{\mathrm{75}}{\mathrm{100}}\: \\ $$$$\mathrm{so}\:\mathrm{by}\:\mathrm{the}\:\mathrm{properties}\:\mathrm{of}\:\mathrm{log}\:, \\ $$$$\mathrm{we}\:\mathrm{can}\:\mathrm{write}\: \\ $$$$\mathrm{log}\:\mathrm{75}\:−\:\mathrm{log}\:\mathrm{100}\: \\…
Question Number 23864 by Tinkutara last updated on 08/Nov/17 $$\mathrm{One}\:\mathrm{mole}\:\mathrm{of}\:\mathrm{steam}\:\mathrm{is}\:\mathrm{condensed}\:\mathrm{at} \\ $$$$\mathrm{100}°\mathrm{C},\:\mathrm{the}\:\mathrm{water}\:\mathrm{is}\:\mathrm{cooled}\:\mathrm{to}\:\mathrm{0}°\mathrm{C}\:\mathrm{and} \\ $$$$\mathrm{frozen}\:\mathrm{to}\:\mathrm{ice}.\:\mathrm{Which}\:\mathrm{of}\:\mathrm{the}\:\mathrm{following} \\ $$$$\mathrm{statements}\:\mathrm{are}\:\mathrm{correct},\:\mathrm{given}\:\mathrm{heat}\:\mathrm{of} \\ $$$$\mathrm{vapourization}\:\mathrm{and}\:\mathrm{fusion}\:\mathrm{are}\:\mathrm{540}\:\mathrm{cal}/ \\ $$$$\mathrm{gm}\:\mathrm{and}\:\mathrm{80}\:\mathrm{cal}/\mathrm{gm}?\:\left(\mathrm{average}\:\mathrm{heat}\right. \\ $$$$\mathrm{capacity}\:\mathrm{of}\:\mathrm{liquid}\:\mathrm{water}\:=\:\mathrm{1}\:\mathrm{cal}\:\mathrm{gm}^{−\mathrm{1}} \\ $$$$\left.\mathrm{degree}^{−\mathrm{1}} \right)…
Question Number 23865 by Tinkutara last updated on 08/Nov/17 $$\mathrm{A}\:\mathrm{man}\:\mathrm{of}\:\mathrm{mass}\:{m},\:\mathrm{standing}\:\mathrm{at}\:\mathrm{the} \\ $$$$\mathrm{bottom}\:\mathrm{of}\:\mathrm{the}\:\mathrm{staircase}\:\mathrm{of}\:\mathrm{height}\:{L} \\ $$$$\mathrm{climbs}\:\mathrm{it}\:\mathrm{and}\:\mathrm{stands}\:\mathrm{at}\:\mathrm{its}\:\mathrm{top}. \\ $$$$\left(\mathrm{1}\right)\:\mathrm{Work}\:\mathrm{done}\:\mathrm{by}\:\mathrm{all}\:\mathrm{forces}\:\mathrm{on}\:\mathrm{man}\:\mathrm{is} \\ $$$$\mathrm{equal}\:\mathrm{to}\:\mathrm{the}\:\mathrm{rise}\:\mathrm{in}\:\mathrm{potential}\:\mathrm{energy} \\ $$$${mgL}. \\ $$$$\left(\mathrm{2}\right)\:\mathrm{Work}\:\mathrm{done}\:\mathrm{by}\:{all}\:\mathrm{forces}\:\mathrm{on}\:\mathrm{man}\:\mathrm{is} \\ $$$$\mathrm{zero}. \\…
Question Number 23863 by Tinkutara last updated on 08/Nov/17 $$\mathrm{From}\:\mathrm{the}\:\mathrm{following}\:\mathrm{data},\:\mathrm{calculate}\:\mathrm{the} \\ $$$$\mathrm{enthalpy}\:\mathrm{change}\:\mathrm{for}\:\mathrm{the}\:\mathrm{combustion}\:\mathrm{of} \\ $$$$\mathrm{cyclopropane}\:\mathrm{at}\:\mathrm{298}\:\mathrm{K}.\:\mathrm{The}\:\mathrm{enthalpy} \\ $$$$\mathrm{of}\:\mathrm{formation}\:\mathrm{of}\:\mathrm{CO}_{\mathrm{2}} \:\left({g}\right),\:\mathrm{H}_{\mathrm{2}} \mathrm{O}\:\left({l}\right)\:\mathrm{and} \\ $$$$\mathrm{propene}\:\left({g}\right)\:\mathrm{are}\:−\mathrm{393}.\mathrm{5},\:−\mathrm{285}.\mathrm{8}\:\mathrm{and} \\ $$$$\mathrm{20}.\mathrm{42}\:\mathrm{kJ}\:\mathrm{mol}^{−\mathrm{1}} \:\mathrm{respectively}.\:\mathrm{The} \\ $$$$\mathrm{enthalpy}\:\mathrm{of}\:\mathrm{isomerisation}\:\mathrm{of}\:\mathrm{cyclopropane}…
Question Number 154896 by maged last updated on 22/Sep/21 $${find}\:{the}\:{following}\:?{please} \\ $$$${S}=\underset{{k}=\mathrm{1}} {\overset{{n}} {\sum}}\frac{\mathrm{1}}{{k}\left({k}+\mathrm{1}\right)\left({k}+\mathrm{2}\right)} \\ $$ Commented by benhamimed last updated on 23/Sep/21 $$\Sigma\frac{\mathrm{1}}{{k}\left({k}+\mathrm{1}\right)\left({k}+\mathrm{2}\right)}=\Sigma\frac{\mathrm{1}}{\mathrm{2}}\left(\frac{\mathrm{1}}{{k}}−\frac{\mathrm{2}}{{k}+\mathrm{1}}+\frac{\mathrm{1}}{{k}+\mathrm{2}}\right) \\…