Answered

A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in given 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.

Answer :

TPS
let the original height of cylinder = 10cm
base radius of cylinder = 3.5cm
so base radius of hemisphere = 3.5cm(same as that of cylinder)

The total surface area would be the sum of curved surface area of cylinder and the surface areas of 2 hemispheres.

surface area of cylinder = 2πrh
surface area of one hemisphere = 2πr²

[tex]TSA=2 \pi rh+2(2 \pi r^2)\\TSA=2 \pi rh+4 \pi r^2\\TSA=2 \pi r(h+2r)\\TSA=2* \frac{22}{7}*3.5(10+2*3.5)=22*(10+7)\\TSA=\boxed{374\ cm^2}[/tex]
The Answer is.....

Given that, 
Radius (r) of cylindrical part = Radius (r) of hemispherical part = 3.5 cm 
Height of cylindrical part (h) = 10 cm 
Surface area of article = CSA of cylindrical part + 2 x CSA of hemispherical part 
= 2 π r h + 2 x 2 π r2 
= 2 π x 3.5 x 10 + 2 x 2 π x 3.5 x 3.5 
= 70 π + 49π 
= 119 π 
= 17 x 22 = 374 cm2 

Hope This Helps....

Other Questions