Difficulty: Easy
Correct Answer: 4 π cm2
Explanation:
Introduction / Context:
Equal-volume partition implies that the volume of the large sphere equals 64 times the volume of each small sphere. Use this to derive each small sphere’s radius, then compute its surface area.
Given Data / Assumptions:
Concept / Approach:
Cancel constants and solve for r. Then S_small = 4πr^2.
Step-by-Step Solution:
R^3 = 64 r^3 ⇒ r^3 = R^3 / 64 = 64 / 64 = 1 ⇒ r = 1 cmS_small = 4πr^2 = 4π * 1^2 = 4π cm2
Verification / Alternative check:
Total surface area is not conserved—only volume is. The question asks for one small sphere, which is 4π cm2.
Why Other Options Are Wrong:
π and 2π are too small; 8π is double the correct area.
Common Pitfalls:
Assuming surface area is conserved during partitioning; it is not.
Final Answer:
4 π cm2
Discussion & Comments