thank you very much
Water is leaking out of an inverted conical tank at a rate of 11,000 cm3/min
at the same time that water is being pumped into the tank at a constant
rate.The tank has height 6 m and the diameter at the top is 4 m.If
the water level is rising at a rate of 20 cm/min when the height of the
water is 2 m, find the rate at which water is being pumped into the
tank. (Round your answer to the nearest integer.)
人气:198 ℃ 时间:2019-09-27 12:54:36
解答
水从一个倒圆锥状的箱里以11000 cm3/分钟的速度流出来.同一时间,水以一个不变的速度被泵入箱里.这个箱子高6m,顶部的直径长4m.如果水位上升的速度为20cm/分钟时水深2m.求水被泵入箱子的速度.(把答案约到最近的整数)我能看懂 就是不会算!半径:高度 = 2m:6mr(2m高的半径):2m →r = (2/3)m2m时面积 = πr^2 = π(2/3m)^2 = (4/9)πm^2 = (40000/9)πcm^2速度:20cm/min*(40000/9)πcm^2 = (800000/9)πcm^3/min = 279252.68cm^3/min279252.68cm^3/min = v - 11000cm^3/minv = 290252cm^3/min答案正确不,好久没做这些题了。。。不对啊我还有两次机会v = 290253cm^3/min对不起,忘记小数点往上约了。这个应该是答案了。顺便一提,如果π是按3.14算,那么答案是290111cm^3/min。
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