If each side of a cube is doubled, how does its volume change?

Difficulty: Easy

Correct Answer: Becomes 8 times

Explanation:


Introduction / Context:
Volume scales with the cube of the linear dimension. If all edges of a 3D object are scaled by a factor k, the volume scales by k^3. Here, each side is doubled, so k = 2, and the new volume is 2^3 = 8 times the original.



Given Data / Assumptions:

  • Original side length a.
  • New side length = 2a.
  • Volume formula for cube: V = a^3.


Concept / Approach:
Compare V′ = (2a)^3 to V = a^3; the ratio V′/V reveals the multiplicative change.



Step-by-Step Calculation:
V′ = (2a)^3 = 8a^3V′/V = 8a^3 / a^3 = 8



Verification / Alternative check:
Try a = 1 ⇒ V = 1; doubling gives a = 2 ⇒ V′ = 8; ratio is 8, confirming.



Why Other Options Are Wrong:
2x, 4x, and 6x correspond to squaring or linear misconceptions; volume scales with the cube of linear change.



Common Pitfalls:
Confusing area scaling (k^2) with volume scaling (k^3).



Final Answer:
Becomes 8 times

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