Find the volume and surface area of a right circular cylinder with a diameter of 200 cm and a height of 100 cm

Question

Thanks 

Answer 1

The volume of a right circular cylinder is ∏r²h, where r is the radius of the circular cross-section and h is the height of the cylinder.

 

Here we have V = ∏(100 cm)²(100 cm) = 1,000,000∏ cm³ (radius is half the diameter) = ∏ m³.

 

For the surface area, we add up the areas of the individual surfaces. For a right cylinder we have the two ends, circles in this case, and the area of the cylindrical face. 

 

For the circular ends, area = ∏r² or ∏(100 cm)² = 10,000∏ cm² and there are two of them, so their combined area is 20,000∏ cm².

 

For the cylindrical surface, imagine unrolling it or flattening it out. Hopefully you can see that you get a rectangle whose height is the height of the cyllinder h, and whose length is the circumference of one of the ends, or 2∏r.

 

The area of this rectangle is length x height = 2∏rh or 2∏(100 cm) (100 cm) = 20,000∏ cm².

 

The total surface area is then the sum of these individual areas: 20,000∏ cm² + 20,000∏ cm² = 40,000∏ cm² = 4∏ m².