Question and Answers Forum

All Questions      Topic List

Logic Questions

Previous in All Question      Next in All Question      

Previous in Logic      Next in Logic      

Question Number 17729 by Tinkutara last updated on 09/Jul/17

A lotus plant in a pool of water is (1/2)  cubit above water level. When  propelled by air, the lotus sinks in the  pool 2 cubits away from its position.  Find the depth of water in the pool.

$$\mathrm{A}\:\mathrm{lotus}\:\mathrm{plant}\:\mathrm{in}\:\mathrm{a}\:\mathrm{pool}\:\mathrm{of}\:\mathrm{water}\:\mathrm{is}\:\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\mathrm{cubit}\:\mathrm{above}\:\mathrm{water}\:\mathrm{level}.\:\mathrm{When} \\ $$$$\mathrm{propelled}\:\mathrm{by}\:\mathrm{air},\:\mathrm{the}\:\mathrm{lotus}\:\mathrm{sinks}\:\mathrm{in}\:\mathrm{the} \\ $$$$\mathrm{pool}\:\mathrm{2}\:\mathrm{cubits}\:\mathrm{away}\:\mathrm{from}\:\mathrm{its}\:\mathrm{position}. \\ $$$$\mathrm{Find}\:\mathrm{the}\:\mathrm{depth}\:\mathrm{of}\:\mathrm{water}\:\mathrm{in}\:\mathrm{the}\:\mathrm{pool}. \\ $$

Commented by alex041103 last updated on 10/Jul/17

What does a ′cubit′mean?I′m sorry for my english.

$$\mathrm{What}\:\mathrm{does}\:\mathrm{a}\:'\mathrm{cubit}'\mathrm{mean}?\mathrm{I}'\mathrm{m}\:\mathrm{sorry}\:\mathrm{for}\:\mathrm{my}\:\mathrm{english}. \\ $$

Commented by mrW1 last updated on 10/Jul/17

1 cubit=45.72 cm

$$\mathrm{1}\:\mathrm{cubit}=\mathrm{45}.\mathrm{72}\:\mathrm{cm} \\ $$

Commented by mrW1 last updated on 10/Jul/17

Answered by mrW1 last updated on 10/Jul/17

D=water depth  D^2 +2^2 =(D+(1/2))^2   ⇒(1/2)(2D+(1/2))=4  ⇒D=((15)/4)=3.75 cubit

$$\mathrm{D}=\mathrm{water}\:\mathrm{depth} \\ $$$$\mathrm{D}^{\mathrm{2}} +\mathrm{2}^{\mathrm{2}} =\left(\mathrm{D}+\frac{\mathrm{1}}{\mathrm{2}}\right)^{\mathrm{2}} \\ $$$$\Rightarrow\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{2D}+\frac{\mathrm{1}}{\mathrm{2}}\right)=\mathrm{4} \\ $$$$\Rightarrow\mathrm{D}=\frac{\mathrm{15}}{\mathrm{4}}=\mathrm{3}.\mathrm{75}\:\mathrm{cubit} \\ $$

Commented by Tinkutara last updated on 11/Jul/17

Thanks Sir!

$$\mathrm{Thanks}\:\mathrm{Sir}! \\ $$

Commented by ajfour last updated on 11/Jul/17

couldn′t follow the geometry..

$$\mathrm{couldn}'\mathrm{t}\:\mathrm{follow}\:\mathrm{the}\:\mathrm{geometry}.. \\ $$

Commented by Tinkutara last updated on 11/Jul/17

Terms of Service

Privacy Policy

Contact: info@tinkutara.com