A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in figure. If the height of the cylinder is 10 cm, and its base is of radius 3.5 cm, find the total surface area of the article.
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AcademicMathematicsNCERTClass 10

Given:

Height of the cylinder, $h=10\ cm$ and radius of the base, $r=3.5\ cm$. 

To do:

We have to find the total surface area of the article.

Solution:

Let $r$ be the radius of the base of the cylinder and $h$ be its height.

This implies,

Total surface area of the article

$=$Curved surface area of the cylinder $+ 2$ (Surface area of a hemisphere)

$=2\pi rh+2( 2 \pi r^{2})$

$=2\pi r( h+2r)$

$=2\times \frac{22}{7}\times3.5( 10+2\times3.5)$

$=374\ cm^{2}$ 

Hence, the total surface area of the article is $374\ cm^{2}$.

raja
Updated on 10-Oct-2022 13:24:36

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