Surface Area of a Sphere

The video tutorial explores the concept of spherical objects, differentiating them from circles, and explains how to calculate the surface area of a sphere using Archimedes' principle. It also covers practical applications, such as determining the amount of material needed to make a football, and introduces hemispheres, explaining their surface areas in both hollow and solid forms.

What is a key difference between a sphere and a circle?

• A sphere can be drawn on paper, while a circle cannot.

• A sphere is three-dimensional, while a circle is two-dimensional.

• A sphere has edges, while a circle does not.

• A sphere is two-dimensional, while a circle is three-dimensional.

Which of the following is true about the surface of a sphere?

• It has multiple surfaces.

• It has edges and vertices.

• It is a single continuous surface.

• It is flat.

How is the surface area of a sphere related to a cylinder?

• The surface area of a sphere is half that of a cylinder.

• The lateral surface area of a cylinder is equal to the surface area of a sphere.

• The surface area of a sphere is unrelated to a cylinder.

• The surface area of a sphere is double that of a cylinder.

If a football has a diameter of 22 cm, what is the radius?

• 5.5 cm

• 44 cm

• 11 cm

• 22 cm

What is the surface area of a solid hemisphere with radius 5 cm?

• 100π cm²

• 25π cm²

• 75π cm²

• 50π cm²

What is the surface area of a hollow hemisphere?

• 3πR²

• πR²

• 2πR²

• 4πR²

What happens when a sphere is divided into two equal parts?

• It forms two circles.

• It forms two solid hemispheres.

• It forms two hemispheres, which can be either solid or hollow.

• It forms two hollow hemispheres.