英语翻译A potter has a fixed volume of clay in the form of a cylinder laying on its side.As he rolls the clay,the length of the cylinder,L,increases while the radius,r,decreases.If the length of the cylinder is increasing at a constant rate of 0.2 cm per second,find the rate at which the radius is changing when the radius is 1.5 cm and the length is 4 cm.
问题描述：
英语翻译
A potter has a fixed volume of clay in the form of a cylinder laying on its side.As he rolls the clay,the length of the cylinder,L,increases while the radius,r,decreases.If the length of the cylinder is increasing at a constant rate of 0.2 cm per second,find the rate at which the radius is changing when the radius is 1.5 cm and the length is 4 cm.
答
有个陶工在滚动一条 圆筒形的柔软陶土, 它的长 (L) 渐增, 它的半径 (r) 渐减.
如果 L 的增速为 每秒 0.2 公分 (0.2 cm/sec), r = 1.5 cm, L = 4 cm.
问题是, 求此时 r 的改变速度.
答
一个陶匠用固定数量的陶土来制作一个圆柱体.当他滚动陶土时,圆柱体的长度,L,增加的同时,它的半径,r,却在减小.如果圆柱体的长度持续每秒增长0.2厘米,半径r是1.5厘米,长度是4厘米时,找出半径的改变速度.