Weather balloons are high altitude balloons that are capable

Weather balloons are high altitude balloons that are capable of reaching an altitude of 40 km (or 25 miles). They are usually filled with hydrogen or helium gas. One such balloon is filled with air that is initially at a temperature of 299 K and at atmospheric pressure. This particular balloon can expand to a maximum diameter of 36 m when it reaches an altitude where the pressure and temperature are 0.028 atm and 190 K respectively. Determine the diameter of the balloon at lift off. Answer not 4.788

Solution

Using ideal gas equation PV=nRT

P₁V₁/T₁=P₂V₂/T₂

0.028*(4/3)*3.14*(18)³/190=1*(4/3)*3.14*(r)³/299

r= 6.357

Diameter= 12.714 metre at lift off