Question

Inside a pressurized cabin, a 1m long barometer tube held vertically
in a mercury tub has 700 mm long mercury column in the tube.
There is some air above the mercury column in the tube. The tube
is slowly tilted by an angle o
60 with the vertical. The mercury
column now is 900 mm along the length of the tube. The value of
pressure in the cabin in units of mm of mercury is