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Q51
(CAPF/2021)
Science & Technology › Basic Science (Physics, Chemistry, Biology) › Quantitative aptitude topics
Answer Verified
Eight metallic balls of one centimetre radius each are melted into one ball. The diameter of the new ball is
Result
Your answer:
—
·
Correct:
C
Explanation
To find the diameter of the new ball, we first calculate the total volume of the eight smaller metallic balls. The volume of a single sphere is given by the formula V = (4/3)πr³. Given each small ball has a radius (r) of 1 cm, the volume of one ball is (4/3)π(1)³ = (4/3)π cm³. Since there are eight such balls, their combined volume is 8 × (4/3)π = (32/3)π cm³. When melted into one large ball with radius R, its volume must equal this total: (4/3)πR³ = (32/3)π. Simplifying this equation, we find R³ = 8, which means R = 2 cm. The diameter of a sphere is twice its radius. Therefore, the diameter of the new ball is 2 × 2 cm = 4 cm.
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