Question

If the volume of a hollow cylinder with inner radius 1 cm is 3π cubic cm, then the thickness is ____cm.

Plz answer immediately

A)1
B)2
C)1.5
D)π
E)Other:

Answer 1

Answer:

Cylinder

A cylinder is a three-dimensional object with two round flat bases and one curved side. It has a curved surface in the middle. The base and the top surface are identical. That means the bases are always parallel and congruent to each other. It has no vertices.

Browse more Topics under Mensuration

Circles

Polygons

Rectangles and Squares

Trapezium, Parallelogram and Rhombus

Area and Perimeter

Cube and Cuboid

Total Surface Area of a Cylinder

Volume of a Cylinder

Now if we look at this figure carefully, we see that there three faces of the cylinder. Two circles and one rectangle. One circle is at the base of the cylinder and other is at the top. Both of these circles are of the same size. Rectangle face is the curved surface of the cylinder. So,

The area of the circle of the cylinder is πr².

The area of two circles will be 2πr².

The radius ‘r’ of a cylinder is the radius of its base. Now, the area of the rectangle = length × breadth. 2πr is the circumference of the circle and h is the height. Area of the curved surface will be = 2πr × h = 2πrh

So the area of the cylinder will be: 2πr² + 2πrh, or

Total Surface Area of Cylinder = 2πr ( r + h )

Where r is the radius and h is the height of the cylinder (the distance between the two bases).