If the density of petrol = 800 kg/m^3, what is the volume of storage tank which will hold 3200kg of petrol and what mass of lead has the same volume as 1600 kg of petrol if density of lead = 11400 kg /m^3.
The density of a substance is defined as the mass of the substance divided by the volume of the substance that is being considered.
Density = mass/volume
The density of petrol is 800 kg/m^3. One m^3 of petrol weighs 800 kg. We have to determine the volume of 3200 kg of petrol.
Using ratios we have 800 kg : 1 ^3, multiplying both sides by 4 gives 3200 kg : 4 m^3. The volume of 3200 kg of petrol is 4 m^3.
The volume of 1600 kg of petrol is 1600/800 = 2 m^3.
As the density of lead is 11400 kg/m^3, the mass of 2 m^3 is 11400*2 = 22800 kg. The mass of lead with the same volume as 1600 kg of petrol is 22800 kg.