Question Number 222961 by Jubr last updated on 12/Jul/25

Answered by mr W last updated on 12/Jul/25

Commented by mr W last updated on 12/Jul/25

$${f}=\mu{N}=\mu{m}\left({g}\:\mathrm{cos}\:\theta+\frac{{v}^{\mathrm{2}} }{{R}}\right) \\ $$$$\:\:=\mathrm{0}.\mathrm{5}×\mathrm{1}×\left(\mathrm{9}.\mathrm{81}×\mathrm{cos}\:\mathrm{60}°+\frac{\mathrm{4}^{\mathrm{2}} }{\mathrm{2}}\right)\approx\mathrm{6}.\mathrm{45}\:{N} \\ $$
Commented by Jubr last updated on 12/Jul/25

$${Thanks}\:{sir}. \\ $$
Commented by Tawa11 last updated on 12/Jul/25

$$\mathrm{Weldone}\:\mathrm{sir}. \\ $$$$\mathrm{Please}\:\mathrm{make}\:\mathrm{the}\:\mathrm{question}\:\mathrm{very}\:\mathrm{complex}. \\ $$$$\mathrm{I}\:\mathrm{want}\:\mathrm{to}\:\mathrm{try}\:\mathrm{the}\:\mathrm{complex}\:\mathrm{part}. \\ $$
Commented by mr W last updated on 12/Jul/25

Commented by mr W last updated on 13/Jul/25

$${a}\:{small}\:{object}\:{of}\:{mass}\:\boldsymbol{{m}}\:{is}\:{released} \\ $$$${from}\:{rest}\:{at}\:\theta=\mathrm{60}°\:{on}\:{the}\:{smooth} \\ $$$${circular}\:{track}\:{with}\:{radius}\:\boldsymbol{{R}}.\: \\ $$$${find}\:{the}\:{period}\:\boldsymbol{{T}}\:{of}\:{the}\:{motion}\: \\ $$$${of}\:{the}\:{object}. \\ $$
Commented by mr W last updated on 17/Jul/25

$${v}={R}\omega \\ $$$$\frac{{mv}^{\mathrm{2}} }{\mathrm{2}}={mgR}\left(\mathrm{cos}\:\theta−\mathrm{cos}\:\theta_{\mathrm{0}} \right) \\ $$$$\omega^{\mathrm{2}} =\frac{\mathrm{2}{g}\left(\mathrm{cos}\:\theta−\mathrm{cos}\:\theta_{\mathrm{0}} \right)}{{R}} \\ $$$$−\frac{{d}\theta}{{dt}}=\omega=\sqrt{\frac{\mathrm{2}{g}\left(\mathrm{cos}\:\theta−\mathrm{cos}\:\theta_{\mathrm{0}} \right)}{{R}}} \\ $$$$−\sqrt{\frac{{R}}{\mathrm{2}{g}}}\int_{\theta_{\mathrm{0}} } ^{\mathrm{0}} \frac{{d}\theta}{\:\sqrt{\mathrm{cos}\:\theta−\mathrm{cos}\:\theta_{\mathrm{0}} }}=\int_{\mathrm{0}} ^{\frac{{T}}{\mathrm{4}}} {dt} \\ $$$${T}=\mathrm{4}\sqrt{\frac{{R}}{\mathrm{2}{g}}}\int_{\mathrm{0}} ^{\theta_{\mathrm{0}} } \frac{{d}\theta}{\:\sqrt{\mathrm{cos}\:\theta−\mathrm{cos}\:\theta_{\mathrm{0}} }}=\mathrm{4}\lambda\sqrt{\frac{{R}}{\mathrm{2}{g}}} \\ $$$${with}\:\lambda=\int_{\mathrm{0}} ^{\theta_{\mathrm{0}} } \frac{{d}\theta}{\:\sqrt{\mathrm{cos}\:\theta−\mathrm{cos}\:\theta_{\mathrm{0}} }} \\ $$$${for}\:\theta_{\mathrm{0}} =\mathrm{60}°:\: \\ $$$$\lambda\approx\mathrm{2}.\mathrm{38401101} \\ $$$${T}\approx\mathrm{6}.\mathrm{743}\sqrt{\frac{{R}}{{g}}} \\ $$
Commented by Tawa11 last updated on 18/Jul/25

$$\mathrm{Ohh}.\:\mathrm{Thank}\:\mathrm{you}\:\mathrm{sir} \\ $$