Answer:
1.4 psi
Explanation:
Before diving into the solution to the question above, let's pick out the parameters needed in solving this problem from the question.
=> The measurement for the outer diameter of the balloon = 20 inches, the measurement for the thickness = 0.012 in, the allowable tensile stress = 1ksi and the allowable shear stress in the balloon = 0.3 ksi.
The first thing to determine is the inner diameter = 20 - 2 × 0.012 in = 19.976 in.
Therefore, the tensile stress:
1000 = k × [19.976/2]÷ 2 × 0.012 = 2.4 psi.
Also, the sheer stress which is also the maximum permissible pressure in the balloon can be calculated below as:
0.3 × 1000 = k × [19.976/2]/ 4 × 0.012 = 1.4 psi.
