Question

JEE MAINS SOLVE THE ATTACHED QUESTIONS ❓

Answer 1

34) A ball falls on the ground from a height of 2.0m and rebounds upto a height of 1.5m. Then the coefficient of restitution is?

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$\red{ \pmb{\sf \qquad : \implies \: h = {e}^{2} \: h_{0} }}$

$\red{ \pmb{ \sf \qquad: \implies \: e = \sqrt{ \dfrac{h}{ h_{0} } } }}$

$\red{ \pmb{\sf{ \qquad : \implies \: e = \dfrac{ \sqrt{3} }{2} \: \: \: \: \: \: \{0ption \: b \}}}}$

35) A pendulum is released from point A as shown in the figure. Find it's speed as it reaches point B.

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$\red{ \pmb {\sf{ \qquad: \implies \: v = \sqrt{ 2gl} }}}$

$\red{ \pmb{ \sf{ \qquad : \implies \: v = \sqrt{2 \: (10) \: (0.5)} }}}$

$\qquad \red{ \pmb {\sf{ : \implies \: v = \sqrt{10} \: m {s}^{ - 1} }}}$

36) A pendulum is released from θ = 90°. Find the speed at θ = 30°. l = 1m.

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$\red{ \pmb{ \sf{ \qquad : \implies \:h =}}} \: \red l \pmb{ \sf \red{\: cos 30 \degree}}$

$\red{ \pmb{ \sf{ \qquad : \implies \: mgh = \dfrac{1}{2}m {v}^{2} }}}$

$\red{ \pmb {\sf{ \qquad : \implies \: {v}^{2} = 2gh }}}$

$\red{ \pmb { \sf{ \qquad : \implies \: {v}^{2} = 2g \times}}} \: \red{l } \red{ \pmb { \sf{\: cos30 \degree }}}$

$\red{ \pmb { \sf { \qquad : \implies \: {v}^{2} = 2 \times 10 \times 1 \times \dfrac{ \sqrt{3} }{2} }}}$

$\red{ \pmb { \sf{ \qquad : \implies \: {v}^{2} = 10 \sqrt{3} }}}$

$\red{ \pmb { \sf { \qquad : \implies \: {v}^{2} \approx4m {s}^{ - 1} }}}$