Question Number 102880 by Dwaipayan Shikari last updated on 11/Jul/20
Commented by Dwaipayan Shikari last updated on 11/Jul/20
$${Sorry}\:{sir}\:.\:{I}\:{did}\:{not}\:{include}\:{it}\:.\:{The}\:{weight}\:{recorder}\:{is}\:{mass} \\ $$$${less}.{The}\:{man}\:{stands}\:{on}\:{it}.{if}\:{Recorder}\:{records}\:\mathrm{72}{kg}\:{as}\:{the} \\ $$$${weight}\:{of}\:{the}\:{man}\:{the}.\:{Here}\:{the}\:{weight}\:{recorder}\:{is}\:{a}\:{trianguler} \\ $$$${platform}.\:{And}\:{it}\:{slides}.\:{Friction}\:{is}\:{along}\:{the}\:{slope} \\ $$$$ \\ $$
Commented by mr W last updated on 11/Jul/20
$${do}\:{you}\:{understand}\:{based}\:{on}\:{the}\:{text} \\ $$$${how}\:{this}\:{recorder}\:{works}\:{and}\:{what} \\ $$$${the}\:{system}\:{does}?\:{does}\:{the}\:{man} \\ $$$${stand}\:{on}\:{the}\:{recorder}\:{which}\:{slideo} \\ $$$${along}\:{the}\:{wedge}?\:{can}\:{the}\:{wedge}\:{move} \\ $$$${on}\:{the}\:{ground}?\:{it}\:{talks}\:{about} \\ $$$${friction},\:{which}\:{friction}\:{is}\:{meant}? \\ $$$${between}\:{the}\:{recorder}\:{and}\:{the}\:{wedge} \\ $$$${or}\:{elsewhere}? \\ $$
Commented by Dwaipayan Shikari last updated on 11/Jul/20
Commented by prakash jain last updated on 11/Jul/20
$$\mathrm{Can}\:\mathrm{you}\:\mathrm{use}\:\mathrm{smaller}\:\mathrm{lines}.\:\mathrm{You}\:\mathrm{may} \\ $$$$\mathrm{be}\:\mathrm{using}\:\mathrm{a}\:\mathrm{tablet}\:\mathrm{but}\:\mathrm{most}\:\mathrm{of}\:\mathrm{us}\:\mathrm{use} \\ $$$$\mathrm{phones}. \\ $$
Commented by Dwaipayan Shikari last updated on 11/Jul/20
$${I}\:{will}\:{maintain}\:{it}\:{from}\:{the}\:{next}\:{time} \\ $$
Answered by mr W last updated on 11/Jul/20
Commented by mr W last updated on 11/Jul/20
$${N}={mg}\:\mathrm{cos}\:\theta \\ $$$${f}=\mu{N}=\mu{mg}\:\mathrm{cos}\:\theta \\ $$$${ma}={mg}\:\mathrm{sin}\:\theta−{f}={mg}\:\mathrm{sin}\:\theta−\mu{mg}\:\mathrm{cos}\:\theta \\ $$$${a}={g}\left(\mathrm{sin}\:\theta−\mu\:\mathrm{cos}\:\theta\right) \\ $$$$\Rightarrow\mu=\left(\mathrm{sin}\:\theta−\frac{{a}}{{g}}\right)\frac{\mathrm{1}}{\mathrm{cos}\:\theta} \\ $$$${mg}−{N}_{\mathrm{1}} ={ma}\:\mathrm{sin}\:\theta \\ $$$$\Rightarrow{a}=\frac{{mg}−{N}_{\mathrm{1}} }{{m}\:\mathrm{sin}\:\theta}=\frac{\mathrm{80}×\mathrm{10}−\mathrm{72}×\mathrm{10}}{\mathrm{80}×\mathrm{0}.\mathrm{6}}=\frac{\mathrm{5}}{\mathrm{3}}\:{m}/{s}^{\mathrm{2}} \\ $$$$\Rightarrow\mu=\left(\frac{\mathrm{3}}{\mathrm{5}}−\frac{\mathrm{5}}{\mathrm{3}×\mathrm{10}}\right)\frac{\mathrm{1}}{\frac{\mathrm{4}}{\mathrm{5}}}=\frac{\mathrm{13}}{\mathrm{24}}=\mathrm{0}.\mathrm{54} \\ $$
Commented by mr W last updated on 11/Jul/20
Commented by Dwaipayan Shikari last updated on 11/Jul/20
$${Thanking}\:{you}.\:{Great}! \\ $$