铝块的体积是V=m/ρ铝=0.810kg/(2.7×10^3kg/m^3)=0.0003m^3
(1)铝块浸没在水中受到的浮力为F水=ρ水Vg=1000×0.0003×10N=3N
(2)铝块浸没在煤油中受到的浮力为F油=ρ油Vg=800×0.0003×10N=2.4N
铝块的重力是G=mg=0.81×10N=8.1N
弹簧秤示数为F示=G-F油=8.1N-2.4N=5.7N
铝块的体积是V=m/ρ铝=0.810kg/(2.7×10^3kg/m^3)=0.0003m^3
(1)铝块浸没在水中受到的浮力为F水=ρ水Vg=1000×0.0003×10N=3N
(2)铝块浸没在煤油中受到的浮力为F油=ρ油Vg=800×0.0003×10N=2.4N
铝块的重力是G=mg=0.81×10N=8.1N
弹簧秤示数为F示=G-F油=8.1N-2.4N=5.7N