Question

Q1. 60 circular plates , each of radius 7 cm and thickness one-third of a cm, are placed one above another to forrm a solid circular cylinder . Find the total surface area and the volume of the cylinder so formed.

Answer 1

Since the thickness is one third of the centimeter there for three plates will form 1 cm
So the height will be 20 cm
The volume will be equal to 3080

Answer 2

Answer:

The total surface area and the volume of the cylinder so formed is $1188 cm^2$ and  $3080 cm^3$ respectively.

Step-by-step explanation:

Radius of 1 plate = 7 cm

Thickens of 1 plate = $\frac{1}{3}$

Thickness of 60 plates=$\frac{1}{3} \times 60 =20 cm$

60 circular plates are placed one above another to form a solid circular cylinder

So, height of cylinder so formed is 20 cm

Total surface area of cylinder = $2 \pi r h + 2 \pi r^2$

                                                = $2 \times \frac{22}{7} \times 7 \times 20 + 2 \times \frac{22}{7} \times 7^2$

                                                = $1188 cm^2$

Volume of cylinder= $\pi r^2h$

                               = $3080 cm^3$

Hence The total surface area and the volume of the cylinder so formed is $1188 cm^2$ and  $3080 cm^3$ respectively.