A drum of a nonflammable, water-insoluble liquid was identified at a fire scene. A sample of the liquid collected from a drum weighs 1.5 lb. and occupies a volume of 0.15 gal. What is the specific gravity of the liquid?

Given parameters

Weight of the box = 120N

Area of the box = 12cm^2

Unknown

Pressure of the box on the floor = ?

Solution

Pressure is the fore exerted by a body per uint area

Pressure = force/area

We need to convert the area into m^2 from cm^2

10000cm^2 = 1m^2

12cm^2 = 12/1000 = 0.0012m^2

Pressure = 120/0.0012 = 100000N/m^2