(1)G=1kg*9.8N/KG=9.8N
F浮=9.8N-4.9N=4.9N
(2)F浮=ρ水gV排
V排=F浮 ÷ (ρ水g)=4.9N ÷ (1.0*10^3kg/m^3 * 9.8N/Kg)= 5* 10^-4 m^3=5*10^5 cm3