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Key words Formula Volume Surface area Perpendicular Height
LO: Calculate the volume and surface area of a Sphere and Cone (Grade A) Key words Formula Volume Surface area Perpendicular Height Slant Height Frustum Vertex Midpoint Cone Sphere
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LO: Calculate the volume and surface area of a Sphere and Cone (Grade A)
Example 1 Cone Curved surface area of a cone = TT r l Total surface area of a cone = TT r l + TT r² Volume = TT r²h 3 Curved surface area = TT x 5 x 12 = = Base area = TT r² = TT x 5² = 78.54 Total surface area = = cm² Volume = TT x 5² x 10 = = cm³ R = 5 H = 10 L = 12
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V = 14241.89cm³ V = 20.94cm³ SA = 3480.89cm² SA = 56.54cm²
LO: Calculate the volume and surface area of a Sphere and Cone (Grade A) V = cm³ SA = cm² V = 20.94cm³ SA = 56.54cm² V = cm³ SA = cm² V = cm³ SA = cm² 8cm
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Calculate the volume and surface area of the sphere below:
LO: Calculate the volume and surface area of a Sphere and Cone (Grade A) Calculate the volume and surface area of the sphere below: r = 4 Volume of a sphere = Surface area of a sphere = Surface area of a sphere = Volume of a sphere = Volume of a sphere = Surface area of a sphere = Volume of a sphere = Surface area of a sphere =
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Find the volume and surface area of these spheres
LO: Calculate the volume and surface area of a Sphere and Cone (Grade A) Find the volume and surface area of these spheres V = 1437cm³ SA = cm² V = 57906cm³ SA = cm² V = cm³ SA = cm² 51.2cm V = mm³ SA = mm² V = cm³ SA = cm² V = cm³ SA = cm² R = 135 mm
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Finding the radius given the volume of a sphere
Find the radius of a sphere of volume 240 𝑐𝑚 3 Volume = 4 3 π 𝑟 3 240 = π 𝑟 3 240 4π 3 = 𝑟 3 57.29 = 𝑟 r = 3.86cm
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Finding the radius given the volume of the cone
Find the radius of a cone of volume 85 𝑐𝑚 3 and height 5cm. V = 1 3 π 𝑟 2 h 85 = π 𝑟 2 x 5 π 𝑥 5 = 𝑟 2 16.23 = 𝑟 2 r = 4.03cm
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This means that the diameter of the ball is the length of the box.
Diameter = 25cm. Therefore radius = 12.5cm a) SA = 4π 𝑟 2 = 4 x π x = 𝑐𝑚 2 b) V = 4 3 π 𝑟 3 V = π 𝑥 = 𝑐𝑚 3
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V of a sphere = π 𝑟 3 V = 𝑥 π 𝑥 5 3 = 𝑐𝑚 3 Since the cone and sphere have the same volume… V of cone = π 𝑟 2 ℎ = π 8 2 ℎ 𝑥 π 𝑥 = h h = 7.81cm
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Past exam Questions Volume of a cylinder: πr²h TT x 5² x 30
LO: Calculate the volume and surface area of a Sphere and Cone (Grade A) Past exam Questions Volume of a cylinder: πr²h TT x 5² x 30 TT x 5² x 30 = 𝑐𝑚 3 4/3 x π x 5³ = 𝑐𝑚 3 Vol of 3 spheres = X 3 = Volume remaining = – = 785.4cm³
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LO: Calculate the volume and surface area of a Sphere and Cone (Grade A)
Past exam Questions A marble paperweight consists of a cuboid and a hemisphere as shown in the diagram. The hemisphere has a radius of 4 cm. Calculate the volume of the paperweight V of sphere = 4 3 π 𝑟 3 = 4 3 π 𝑥 = 𝑐𝑚 3 V of hemisphere = ÷ 2 = 𝑐𝑚 3 V of cuboid = Area x height = 10 x 10 x 5 = 500 𝑐𝑚 3 Total volume = = 𝑐𝑚 3
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LO: Calculate the volume and surface area of a Sphere and Cone (Grade A)
Past exam Questions A hemispherical bowl of radius 6 cm has the same volume as a cone of perpendicular height 27 cm. Not drawn accurately Calculate the base radius, r, of the cone.
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LO: Calculate the volume and surface area of a Sphere and Cone (Grade A)
Past exam Questions A cone has base radius 6 cm and height h = 9 cm. A smaller cone of base radius 2 cm and height 3 cm is cut from the top. The remaining frustum has dimensions as shown. Calculate the volume of the frustum Volume of the frustum = Vol of the large cone – Vol of small cone 1 3 𝑥 π 𝑥 6 2 𝑥 𝑥 π 𝑥 2 2 𝑥 3 = 𝑐𝑚 3
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Past exam Questions Calculate the volume and surface area:
LO: Calculate the volume and surface area of a Sphere and Cone (Grade A) Past exam Questions . 10cm 16cm Calculate the volume and surface area:
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LO: Calculate the volume and surface area of a Sphere and Cone (Grade A)
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A cylinder of radius 5cm and height 6cm is melted and recast into a cone of radius 3cm. What is the height of the cone? V=π 𝑟 2 ℎ V = π x x 6 V = 𝑐𝑚 3 V = 1 3 π 𝑟 2 h 471.2= 1 3 π 𝑟 2 ℎ
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A cone of radius 6cm and height 4cm is melted and recast into spheres of radius 1cm. How many spheres are made? Volume of cone = 1 3 π 𝑟 2 ℎ V = 1 3 π 6 2 𝑥 4 = 𝑐𝑚 3 Volume of sphere = 4 3 π 𝑟 3 = 4 3 π = 4.19 𝑐𝑚 3 Number of spheres = ÷ 4.19 = 36 spheres ( if the answer is not a whole number, give the answer as a whole number, rounded down)
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