Sheet thickness from volume and spread area: Half a cubic meter of gold is hammered into a sheet that covers 1 hectare. Find the sheet’s thickness in cm.
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A0.5 cm
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B0.05 cm
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C0.005 cm
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D0.0005 cm
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E0.00005 cm
Answer
Correct Answer: 0.005 cm
Explanation
Introduction / Context:Volume conservation gives thickness when a volume is spread uniformly over a known area. This tests conversions between meters and centimeters and hectares to square meters.
Given Data / Assumptions:
- Volume V = 0.5 m^3
- Area A = 1 hectare = 10,000 m^2
- Thickness t = V / A (in meters), then convert to centimeters
Concept / Approach:Use t = V / A. Convert meters to centimeters by multiplying by 100 (1 m = 100 cm).
Step-by-Step Solution:t (in m) = 0.5 / 10000 = 0.00005 mt (in cm) = 0.00005 * 100 = 0.005 cm
Verification / Alternative check:Back-check: Area * thickness = 10,000 m^2 * 0.00005 m = 0.5 m^3, confirming consistency.
Why Other Options Are Wrong:0.5 cm and 0.05 cm are 100× and 10× too thick; 0.0005 cm and 0.00005 cm are 10× and 100× too thin.
Common Pitfalls:Confusing cm with m; using 1 hectare = 1000 m^2 (incorrect); forgetting to multiply by 100 when converting thickness to cm.
Final Answer:0.005 cm