What is the pressure of the gas in this mercury manometer if h = 89 mm and atmospheric pressure is 775 mmhg?

The pressure of the gas is 686 mmhg.

If h = 89 mm

and atmospheric pressure = 775 mmhg

Pressure of the gas = ?

We can find the pressure of the gas by finding the difference between both values.

pressure of the gas = 775 mmhg - 89 mm = 686 mmhg