Question

An oil of specific gravity 0.8 is contoined in a tube to depth of 80 cm ditermine the gauge pressure at this depth in KN/m2

Answer 1

Pressure is represented in terms of height of any liquid is , P = H*d*g

Where H is height of the liquid, d is the density of the liquid and g the gravitational constant.

Now we know P = 80* 1000* 9.8

And in terms of oil of specific gravity 0.8

P = H * 0.8*1000*9.8

One can find the height of the oil to be 100 m by using the above equation.

The pressure of h meter of oil=hd(oil)g…………….(1)

The pressure of h' meter of water=h'd(water)g…………..(2)

Comparing (1) with (2),

hd(oil)g=h'd(water)g. Therefore,

h=h' d(oil)/d(water).

But, d(oil)/d(water)= specific gravity of oil=0.8 given. Then,

h meter of oil is equivalent to 0.8 m of water.