Problem 1.29 [Difficulty: 1]
Given: Den sity of mercury.
Find: Specific gravity, volume and weight.
Solution: Use basic definitions
SG ρ
ρw
=From Appendix A ρw1.94 slug
ft3
⋅= so SG 26.3
1.94
=SG 13.6=
v1
ρ
=so v1
26.3
ft3
slug
⋅0.3048m⋅
1ft⋅
⎛
⎜
⎝
⎞
⎠
3
×1 slug⋅
32.2 lbm⋅
×1 lbm⋅
0.4536kg⋅
×= v 7.37 10 5−
×m3
kg
=
γρg⋅=
Hence on earth γE26.3 slug
ft3
⋅32.2×ft
s2
⋅1 lbf⋅s2
⋅
1 slug⋅ft⋅
×= γE847 lbf
ft3
=
On the moon γM26.3 slug
ft3
⋅5.47×ft
s2
⋅1 lbf⋅s2
⋅
1 slug⋅ft⋅
×= γM144 lbf
ft3
=
Note that mass-based quantities are independent of gravity