A tank of 2400m3 volume and 12 depth, has a vertical side and horizontal bottom. Find how many tonnes of oil of RD 0.7 it can hold, allowing 2% of the tank for the expansion .state the ullage of loading.

Given :
The volume of the tank = 2400m³
Depth of tank =12m
RD =0.7

According to the question, 2% of the volume is allowed for expansion.
As we know that

Density = Mass/ Volume
Since volume =(L x B x H)
= 2400m³( given )

So, Area = (volume / depth)
= (2400/12)
=200m²

Mass  =  ( volume x density)
Mass  =  (2400×0.7)
 =1680 t

Since 2% of the volume of the tank allowed for expansion
 = (2/100) x 2400
 = 48m³

Volume of the oil = (volume of the tank – free space )
= ( 2400 -48)
= 2352 m³

Mass of the oil = (volume x density)
 =2352 x 0.7

Depth of oil = (volume of oil /area)
= 2352/(L x B)
= (2352/ 200)
=11.76 m

Hence, Ullage = (12-11.76)
                           = 0.24m.