R=r+壁厚 --- ①
V= π(R²-r²)h --- ② 把①代入②得:
V=π [ ( r+壁厚)²-r² ] h
V=π [ r²+2 r 壁厚+壁厚²- r² ] h
V=(2 r+壁厚) π × 壁厚 × h
提示:题目里(r+壁厚) π*壁厚*长度漏了2
R=r+壁厚 --- ①
V= π(R²-r²)h --- ② 把①代入②得:
V=π [ ( r+壁厚)²-r² ] h
V=π [ r²+2 r 壁厚+壁厚²- r² ] h
V=(2 r+壁厚) π × 壁厚 × h
提示:题目里(r+壁厚) π*壁厚*长度漏了2