Réponse :
Exercice 1 :
-> Il faut faire attention si on converti le numérateur ( masse) ou dénominateur (volume) et des conversion
a) 1,3 kg/L = 1300 g/L = 1300/1000 g/mL = 1,3 g/mL
b) 789 g/L = 0.789 g/mL
c) 1 m^3 = 1000 L
1300 kg/m3 =1.3 kg/L = 1300 g*L = 1.3g/mL
d)0.8 kg/m3 = 0.0008 kg/L = 0.8g/L = 0.0008 g/mL soit 8.10^-4 g/mL
Exercice 2 :
p=m/v = 40/15 =2.667 g/mL
Exercice 3
a)p=m/v = 158/200 =0.79 g/mL
b) 5L = 5000 g
soit p=m/v -> m = p*v = 0.79 * 5000 =3950 g
Exercice 4 : p =1.03kg/L = 1,03 g/mL
p=m/v -> m=p*v =1,030 *150=154,5 g
Exercice 5)
p=1,025 kg/m3 = 1,025.10^-3 kg/L = 1,025 g/L = 1,025.10^-3 g/mL
a)1000 L = 1000.10^3 mL
Soit m = p*v = 1,025.10^-3 * 1000.10^3 =1025 g
b) p=m/v -> V =m/P = 300/1,025.10^-3 =292 683 mL = 292,683 L soit environ 292,7L
Voila !
