Question

An oil of specific gravity 0.8 is contained in a tube to a depth of 80 cm. Determine the gauge pressure at this depth in kN/m2.

Answer 1

Given that :- specific gravity $=0.8$ and depth $80cm$

As we have to determine the gauge pressure,

We know that,

$P = H*d*g$

Where H is height,

d is the density,

g the gravitational constant.

Now,$P = 80* 1000* 9.8$

 In the terms of specific gravity $0.8$

$P = H * 0.8*1000*9.8$

By using above equation we can find the height is to be $100m$

Equation for h, metre

$oil = hd (oil) g$   ….(1)

The pressure of h' meter

$water=h'd(water)g$    …..(2)

Now, by comparing both the equation we get,

$hd(oil)g=h'd(water)g$

Therefore,

$h=h' \frac{d(oil)}{d(water)}$

But,

$\frac{d(oil)}{d(water)}=0.8$

Then, h metre of oil equals 0.8 metre of water.

Answer 2

Given that :- specific gravity 0.8 and depth  80cm

As we have to determine the gauge pressure,

We know that,

Where H is height,

d is the density,

g the gravitational constant.

Now,

In the terms of specific gravity 0.8

$P=H*0.8*1000*9.8$

By using above equation we can find the height is to be  100m

Equation for h, metre

oil=hd(oil)g   ….(1)

The pressure of h' meter    …..(2)

Now, by comparing both the equation we get,

hd(oil)g=h'd(water)g

Therefore,

But,

Then, h metre of oil equals 0.8 metre of water.