Question

Calculate the hight of a water column which will exert on its bade the same pressure as the 70cm column of mercury . Density of mercury is 13.6gm-3

Answer 1

Pressure at the place remains the same for both water and mercury.

Pressure exerted by mercury = density of mercury * height of mercury column * g (acc. due to gravity)

=> Pressure exerted by mercury = 13.6 * 70 * g
=> Pressure exerted by mercury = 952 g.

Pressure exerted by water = density of water * height of water column * g (acc. due to gravity)

=> Pressure exerted by water = 1 * h *g
=> Pressure exerted by water = h g.

Now, According to question,

952* g = h* g
=> h = 952 cm.

Therefore, the height of water column which will exert on its base the same pressure as the 70 cm column of mercury is 952 cm. (Answer)

Simply

We know,
P=density×height of liquid column×g
P(mercury)=13.6×980×70=932960dyne\cm
Now h of wayercolumn with same ptesdure=h
=pressure\density×g
=932960/980
=952cm