英语翻译

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.

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.