Question

Question :-

A spherical valve of a tank is 21 cm in diameter. Calculate the surface area and volume

Answer 1

Given :-  

• Diameter of spherical valve of a tank is 21 cm  

To Find :-  

• It’s surface area and volume  

Solution :-  

~Here, we’re given the diameter of a spherical valve of a tank and we need to find the surface area and the volume of that valve . Firstly we will find the radius by the given diameter and then find the answers by applying respective formulas.  

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Finding the Radius :-  

${\large{\boxed{\underline{\mathrm{\orange{Radius=\dfrac{Diameter}{2}}}}}}}$

$\sf \leadsto \dfrac{21}{2}$

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Finding the Surface area :-  

${\large{\boxed{\underline{\mathrm{\orange{Surface\;area\;of\;Sphere=4\pi r^{2}}}}}}}$

$\sf \leadsto 4 \times \dfrac{22}{7} \times \dfrac{21}{2} \times \dfrac{21}{2}$

$\sf \leadsto 22 \times 3 \times 21$

$\sf \leadsto 1386\;cm^{3}$

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Finding the Volume :-  

${\large{\boxed{\underline{\mathrm{\orange{Volume\;of\;sphere= \dfrac{4}{3} \pi r^{3}}}}}}}$

$\sf \leadsto \dfrac{4}{3} \times \dfrac{22}{7} \times \dfrac{21}{2} \times \dfrac{21}{2} \times \dfrac{21}{2}$

$\sf \leadsto 11 \times 21 \times 21$

$\sf \leadsto 4851 \; cm^{2}$

 

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Therefore ,  

→ Volume of the spherical tank is 1386 cm³ and surface area is 4851 cm²  

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Answer 2

A sphere is a perfectly round geometrical 3-dimensional object. It can be characterized as the set of all points located distance rr (radius) away from a given point (center). It is perfectly symmetrical, and has no edges or vertices.

A sphere with radius rr has a volume of \frac{4}{3} \pi r^3  

3

4

​  

πr  

3

 and a surface area of 4 \pi r^24πr  

2

.