Question

一个空心铁球 吊在弹簧秤下静止示数为7.8牛 将他浸没在水中 弹簧秤示数ewing4牛 问空心体积是多少?

Answer 1

F浮=G-G’=7.8N-4N=3.8N V球=V排 = F浮/ ρ水g = 3.8N/1.0×103kg/m3 × 10N/kg = 3.8×10-4m3

V铁 = G/ ρ铁g = 7.8N/7.8×103kg/m3 × 10N/kg = 1 ×10-4m3

V空=V球-V铁 =3.8×10-4m3-1 ×10-4m3=2.8×10-4m3