題目是:
Assume that a shphere of ice melts at a rate proportional
to its surface area, retaining a spherical shape. Interpret
melting as a reduction of volume with respect to time
有2個要求的答案
1.Determine an expression for the volume of ice ar any time t.
2.How long that the volume will be one-half of the origin, if V(0)=10cm^3.
我只知道表面積A = 4兀r^2
V = 4/3 * 兀r^3 , r^3= 3V/4兀
r=(3V/4兀)^1/3 代入 A(表面積)
得到A = 4兀*(3V/4兀) ,
dV/dt= KA
之後就不太會算了
請高手幫一下忙,感謝