m**********d
发帖数: 1818 | 1 虚心请教：
有一个平面object,它的second-moments是area吗？ | l*****d
发帖数: 754 | 2 If first-moment is the center of mass (namely average of r),
then the second-moment should be the average of r^2
【在 m**********d 的大作中提到】
: 虚心请教：
: 有一个平面object,它的second-moments是area吗？
| m**********d
发帖数: 1818 | 3 thanks
but how to find the ellipse which has the same second-moments as this region
???
is there only one answer?
【在 l*****d 的大作中提到】
: If first-moment is the center of mass (namely average of r),
: then the second-moment should be the average of r^2
|
|
