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Surface Area and Volume of Spheres Section 4.9 Standard: MM2G4 ab Essential Questions: How do I find the surface area and volume of spheres? How does changing the radius or diameter affect the surface area and volume?. Formula: Surface Area of a Sphere.
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Surface Area and Volume of Spheres Section 4.9 Standard: MM2G4 ab Essential Questions: How do I find the surface area and volume of spheres? How does changing the radius or diameter affect the surface area and volume?
Find the surface area of the sphere, given that the radius is 9 inches. S = 4(9)2 S = 324 S ≈ 1017.88 in.2
2. Find the surface area of the sphere, given that the diameter is 10 inches. S = 4(5)2 S = 100 S ≈ 314.16 in.2 d = 2r 10 = 2r 5 = r
3. Find the surface area of the sphere, given that the circumference of the sphere is ft. S = 4(4)2 S = 64 C = 2r 8 = 2r 4 = r S ≈ 201.06 ft2
4. Find the volume of the sphere, given that the radius is 8 inches. V ≈ 2144.66 in.3
5. Find the volume of the sphere, given that the diameter is 10 inches. d = 2r 10 = 2r 5 = r V ≈ 523.60 in.3
6. Find the volume of the sphere, given that the circumference of the sphere is ft. C = 2r 8 = 2r 4 = r V ≈ 268.08 ft3
Complete the table. 4 6 4:6 or 2:3 4 6 4:6 or 2:3 4 9 4:9 or 4:9 16 36 16:36 or 4:9
Complete the table. 2a 2b a : b 2a 2b a : b a2 b2 a2 : b2 4a2 4b2 a2 : b2 a3 : b3
a : b Scale Factor _____________ Area Ratios _______________ Volume Ratios _______________ a2 : b2 a3 : b3
7. Two spheres have diameters 24 and 36. a. What is the ratio of the areas? b. What is the ratio of the volumes? Ratio of volumes: 24 and 36 Radii: Ratio of radii: 24 : 36 or 2 : 3 Ratio of areas: 22 : 32 or 4 : 9 23 : 33 or 8 : 27
8. A sphere has a radius of 6 meters. The radius of a second sphere is 3 meters. (a.) How does the surface area of the second sphere compare the to surface area of the first sphere? (b.) Volumes? Ratio of radii: 3 : 6 or 1 : 2 or 1: 4 (a). Ratio of areas: 12 : 22 The second sphere is ¼ the size of the first. (The area of the second sphere is 4 times smaller) or 1: 8 13 : 23 (b). Ratio of volumes: The second sphere is 1/8 the size of the first. (The volume of second sphere is 8 times smaller)
9. The radius of a sphere is 2.4 cm. (a.) How will the surface area change if the radius is doubled? (b.) Volume? Double the radius: 2(2.4) = 4.8 Ratio of radii: 2.4 : 4.8 or 1 : 2 12 : 22 or 1 : 4 Ratio of surface areas: The surface area is 4 times larger if the radius is doubled. Ratio of volumes: 13 : 23 or 1 : 8 The volume is 8 times larger if the radius is doubled.
10. Find the surface area of one hemisphere of a circle if the circumference of a great circle of the sphere is 7 cm. C = 2r 7 = 2r 7/2 = r Area of base of hemisphere: A = r2 A = (3.5)2 A = 12.25 A ≈ 38.48 cm2 Surface area of entire sphere: S = 4r2 S = 4 (3.5)2 S = 49 S ≈ 153.93 cm2 Surface area of hemisphere ≈ 153.93 cm2 + 38.48 cm2 ≈ 192.41 cm2