Let’s solve each problem one by one, using π = 3.14 and rounding to the nearest hundredth where necessary.
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Problem 10:
*A cone has a slant height of 17 cm and the base of the cone has a diameter of 14 cm. Find the height of the cone and then the volume.*
- Diameter = 14 cm → Radius (r) = 7 cm
- Slant height (l) = 17 cm
Use the Pythagorean Theorem for cones:
h² + r² = l²
→ h² + 7² = 17²
→ h² + 49 = 289
→ h² = 240
→ h = √240 ≈
15.49 cm (rounded to nearest hundredth)
Now, volume of a cone:
V = (1/3)πr²h
→ V = (1/3)(3.14)(7²)(15.49)
→ V = (1/3)(3.14)(49)(15.49)
→ First, 49 × 15.49 = 759.01
→ Then, 3.14 × 759.01 ≈ 2384.2914
→ Divide by 3: 2384.2914 ÷ 3 ≈
794.76 cm³
✔ Answer: Height = 15.49 cm, Volume = 794.76 cm³
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Problem 11:
*Sarah bought an extra-large soda... cup has diameter 5 inches, height 10 inches, filled 3/4 full. How many cubic inches of soda?*
Volume of cylinder:
V = πr²h
- r = 5/2 = 2.5 in
- h = 10 in
→ V = 3.14 × (2.5)² × 10
→ V = 3.14 × 6.25 × 10
→ V = 3.14 × 62.5 =
196.25 in³ (full volume)
She filled 3/4:
→ 196.25 × 0.75 =
147.19 in³
✔ Answer: 147.19 cubic inches
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Problem 12:
*Erin brings a spherical container with radius 5 inches, fills with coconut flour. Each cubic inch weighs 0.35 oz. Cost $0.12 per oz.*
a)
Volume of sphere:
V = (4/3)πr³
→ V = (4/3)(3.14)(5³)
→ V = (4/3)(3.14)(125)
→ V = (4/3)(392.5) = 523.333... ≈
523.33 in³
b)
Weight in ounces:
Each in³ = 0.35 oz → 523.33 × 0.35 =
183.17 oz
c)
Cost: $0.12 per oz → 183.17 × 0.12 =
$21.98
✔ Answers:
a) 523.33 in³
b) 183.17 oz
c) $21.98
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Problem 13:
*Ice cream cone: slant height 10 in, height 8 in.*
a)
How wide is the opening at the top? → That’s the diameter of the base.
Use Pythagorean Theorem:
r² + h² = l²
→ r² + 8² = 10²
→ r² + 64 = 100
→ r² = 36 → r = 6 in →
diameter = 12 in
b)
If ice cream is leveled off at the top, how many cubic inches? → Volume of cone
V = (1/3)πr²h
→ V = (1/3)(3.14)(6²)(8)
→ V = (1/3)(3.14)(36)(8)
→ V = (1/3)(3.14)(288) = (1/3)(904.32) =
301.44 in³
✔ Answers:
a) 12 inches wide
b) 301.44 cubic inches
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Problem 14:
*Dixie Cup Company: changing from cone to cylinder, same radius and height. Cone holds 4 oz. How much will cylinder hold?*
Volume of cone = (1/3)πr²h
Volume of cylinder = πr²h → So cylinder holds
3 times the volume of the cone with same r and h.
→ If cone holds 4 oz, cylinder holds 4 × 3 =
12 oz
✔ Answer: 12 ounces
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Problem 15:
*Hemisphere with radius 3 inches. How many cubic inches of liquid to fill it?*
Volume of hemisphere = (1/2) × volume of sphere =
(2/3)πr³
→ V = (2/3)(3.14)(3³)
→ V = (2/3)(3.14)(27)
→ V = (2/3)(84.78) =
56.52 in³
✔ Answer: 56.52 cubic inches
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✔ Final Answers Summary:
10. Height = 15.49 cm, Volume = 794.76 cm³
11. 147.19 in³
12. a) 523.33 in³, b) 183.17 oz, c) $21.98
13. a) 12 in, b) 301.44 in³
14. 12 ounces
15. 56.52 in³
Let me know if you’d like diagrams or step-by-step breakdowns for any!
Parent Tip: Review the logic above to help your child master the concept of volume of a cylinder word problems worksheet.