A ball is dropped from a height of 80,m on a surface which is at rest. height attainded by ball afte

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5.Work, Energy, Power and Collision

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A ball is dropped from a height of $80\,m$ on a surface which is at rest. Find the height attainded by ball after $2^{nd}$ collision if coefficient of restitution $e = 0.5$ ............ $\mathrm{m}$

A

$5$

B

$10$

C

$40$

D

$80$

Solution

$\mathrm{h}_{\mathrm{n}}=\mathrm{e}^{2 \mathrm{n}} \mathrm{h} \quad \mathrm{h}_{2}=\mathrm{e}^{4} \mathrm{h}$

$\mathrm{h}_{2}=\left(\frac{1}{2}\right)^{4} \mathrm{h} \Rightarrow \frac{1}{16} \times 80=5 \mathrm{m}$

Standard 11

Physics

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