题目
Water is leaking out from a cylinder container at the rate of 0.31 m^3 per minute. 10 minutes later, the water level decreases 0.25 meter, what is value of the radius?
解析
10分钟内从圆柱容器中漏出的水的体积为:\( 10 × 0.31 = 3.1 \)立方米。
圆柱体积公式为\( 体积 = \pi × r^2 × 高度 \),代入已知条件:
\( \pi × r^2 × 0.25 = 3.1 \)
取\( \pi ≈ 3.14 \),则:
\( 3.14 × r^2 × 0.25 = 3.1 \)
解得\( r ≈ 2 \)(近似值)。
答案:D