Question

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

Answer 1

Answer:

3.5 cm

soid layer

cyclinder

Answer 2

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

= 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