A submarine moves horizontally in sea and has its axis 15 m below the surface of water. A pitot-tube properly placed just in front of the submarine and along its axis is connected to the two Limbs of...

A submarine moves horizontally in sea and has its axis 15 m below the surface of water. A pitot-tube
properly placed just in front of the submarine and along its axis is connected to the two Limbs of a U tube
containing mercury. The difference of mercury level is found to be 170 mm. Find the speed of the
submarine knowing that the sp.gr. of mercury is 13.6 and that of sea water is 1.026 with respect of fresh
water.