Jawabanmu

2014-04-05T22:12:22+07:00
Wu = 70 N
Wa = 1/2 Wu = 35 N
g = 10 m/s

Jawab

a) Fa = Wu - Wa = 70-35 = 35 N
b) Fa = Rho air . V . g
35 = 1000.V.10
V = 35/10^4 = 35.10^-4 m^3
c) Rho benda = m/V
Wu/g x 1/V
= 70/10 x 1/35.10^-4
= 7/35.10^-4
= 10^4/5
= 2.10^3 kg/m^3

Koreksi kalo salah :)

No c kurang ngerti
Kenapa rumusnya 1/v
w = mg -> m = w/g
rho = m/v -> rho = w/g/v ato w/g x 1/v