# Volume and Surface Area of Sphere. 2nd Grade of Secondary School

## Explaining about Volume and Area of Sphere. The learning material resources for media taken from New Syllabus Mathematics book (7ed), published by Shinglee.

MathematicsVolumeSurface AreaSphereSecondary School

# Volume and Surface Area of Sphere. 2nd Grade of Secondary School

Created 3 years ago

Duration 0:11:19
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Explaining about Volume and Area of Sphere. The learning material resources for media taken from New Syllabus Mathematics book (7ed), published by Shinglee.
Slide Content
1. ### Slide 1 - Mathematics

• Volume and Surface Area of Spheres
• 2nd grade of Secondary School
• By: I Putu Eka Prana Yoga
2. ### Slide 2 - Learning Objectives

• Use Formulas to calculate the volume and the surface area of spheres.
• Solve problems involving the volume and the surface area of composite solids made up of spheres.
3. ### Slide 3 - Learning Agenda

• Classroom Discussion
• Types of Spheres
• Volume and Surface of Spheres
• Exercise
4. ### Slide 4 - What are Spheres?

• Soccer Ball
• Globe
• Crystal Ball
5. ### Slide 5 - Classroom Discussion

• Is the King’s Crown Made of Pure Gold?
• One day, Archimedes is asked by king to find out whether his crown was made of pure gold or whether the goldsmith had cheated. The real problem lies in finding the volume of the crown.
6. ### Slide 6 - Classroom Discussion

• Archimedes realized that a sinking solid displaces as amount of water that is equal to the volume of the solid. To find the volume of the crown, we can fill up the container as shown in fig. with water until it overflows before putting in the crown. The volume of water displaced into the container as shown in fig. is equal to the volume of the crown.
7. ### Slide 7 - Investigation

• Using displacement method before, Archimedes discover a formula to find a sphere. Archimedes filled the cylinder with water and placed the sphere inside it.
• Archimedes found out that the volume of water displaced was equal to of the volume of the cylinder. This was one of the greatest discoveries.
8. ### Slide 8 - Investigation

• Volume of cylinder =
• Volume of Sphere =
• =
• =
• =
• =
9. ### Slide 9 - Investigation

• A ball bearing (which is spherical in shape) has a radius of 0.3 cm. Find:
• The volume of the ball bearing
• The mass of 6000 identical ball bearing if they are made of steel of density 7.85 g/
10. ### Slide 10 - The volume of the ball bearing =

• =
• =
• =
• The mass of 6000 identical ball = volume of 6000 ball bearings density
• =
• =

12. ### Slide 12 - Investigation

• Length of second piece of twine =
• Curved surface area of sphere =
• =
• =
• =
• =
13. ### Slide 13 - Example 2

• A solid sphere has a diameter of 14 cm. Find its surface area.
• Surface area of sphere =
• =
• =
• =
14. ### Slide 14 - Example 2

• Curved surface area of solid hemisphere = 175
• =
• =
• =
• =
• =
• A solid hemisphere has a curved surface area of 175 . Find its radius.