12) What is the volume of mercury in cm3, if the mass (m) of mercury is 136 grams (g) and density (r) of mercury is 13.6 g/cm3?

13) What is the block weighs (W) in kg, if volume (V) is 320 cm3 and density 8.9 g/cm³?

14) What is the specific gravity of the metal, if the weighs 6.5 kgf in air and 3.5 kgf in water?

15) What is the weight force of a car has a mass of 800 kg?(Take g = 9.81m/sec)