An airship of 100m3 in size is launched from sea level and it gradually attains height until it reaches the desired altitude. A manometer measuring the gage pressure of the inside filled Helium gas show a reading of 1.2 bar at the altitude of A meters from the ground. Manometer shows reading of 2 bar when it reaches to a height of B meters. Assume; Density of air at point A = 1.00 kg/m3 and at Point B= A = 0.80 kg/m3. You can also assume average density = 0.9 kg/m3 where required. Consider temperature inside the balloon = 10°C and negligible change in temperature during the process.   (a) Calculate external atmospheric pressure difference between Point A and B (b) Neglecting the effect of altitude on local gravitational acceleration, determine the height attained from A to B.

An airship of 100m3 in size is launched from sea level and it gradually attains height until it reaches the desired altitude. A manometer measuring the gage pressure of the inside filled Helium gas show a reading of 1.2 bar at the altitude of A meters from the ground. Manometer shows reading of 2 bar when it reaches to a height of B meters. Assume; Density of air at point A = 1.00 kg/m3 and at Point B= A = 0.80 kg/m3. You can also assume average density = 0.9 kg/m3 where required. Consider temperature inside the balloon = 10°C and negligible change in temperature during the process.  
(a) Calculate external atmospheric pressure difference between Point A and B (b) Neglecting the effect of altitude on local gravitational acceleration, determine the height attained from A to B.