Difficulty: Medium
Correct Answer: 51 min 12 s
Explanation:
Introduction / Context:Time = (volume to fill) / (flow rate). Compute the cone volume and the pipe’s volumetric flow rate from its cross-sectional area and linear speed.
Given Data / Assumptions:
Concept / Approach:Flow rate Q = area * speed = πr^2 * v. Cone volume V = (1/3)πR^2h. Time t = V / Q.
Step-by-Step Solution:
Q = π * (0.0025)^2 * 10 = 6.25×10^-5 π m^3/minV = (1/3)π * (0.20)^2 * 0.24 = 0.0032 π m^3t = V/Q = (0.0032 π) / (6.25×10^-5 π) = 51.2 min = 51 min 12 sVerification / Alternative check:π cancels; ensure consistent SI units (metres). 0.2^2 = 0.04; 0.04*0.24/3 = 0.0032.
Why Other Options Are Wrong:Small deviations come from rounding or mm–cm–m conversion errors.
Common Pitfalls:Using radius as 5 mm (not diameter); forgetting 1/3 in cone volume; mixing cm and m.
Final Answer:51 min 12 s
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