4) A paint roller has a diameter of 10cm and height of 21 cm. How much area can the paint roller cover eight revolution?
Answers
Answer:
251.6 cm²
Step-by-step explanation:
Given that the radius(r) of the paint roller is 5cm.
Therefore, Permimeter of the roller is=2πr
=(2*22/7)(5)
=(6.29)(5)
=31.45
Therefore in 1 revolution the roller will paint 31.45 cm².
Therefore in 8 revolutions the roller will paint (31.45*8)=251.6 cm².
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Answer:
- 5280 cm² can be paint roller cover in eight revolutions
Step-by-step explanation:
Given:
- A paint roller has a diameter of 10cm and height of 21 cm.
To Find:
- Area can the paint roller cover eight revolution?
Solution:
- Diameter = 10 cm
- Radius = 10/2 = 5cm
Using formula:
- CSA of cylinder = 2πrh
⟼ Curved surface area = 2 × 22/7 × 5 × 21
⟼ Curved surface area = 2 × 22 × 5 × 3
⟼ Curved surface area = 44 × 5 × 3
⟼ Curved surface area = 660 cm²
Now,
⟼ Area = Curved surface area ×8
⟼ Area = 660 × 8
⟼ Area = 5280 cm²
∴ 5280 cm² can be paint roller cover in eight revolutions