Question

An air filled balloon is at a depth of $1km$ below the water level in an ocean. Determine the normal stress on the balloon
(atmospheric pressure $={10}^{5}Pa)$.

• A. $9.8\times {10}^{5}Pa$
• B. $9.9\times {10}^{5}Pa$
• C. $9.8\times {10}^{3}Pa$
• D. $9.9\times {10}^{6}Pa$

Answer 1

The correct option is D $9.9\times {10}^{6}Pa$

Stress on balloon

Height = 1000 m

Density of water = 1000 Kg/m³

$=Atmosphericpressure+h\rho g$

$={10}^5+(1000\times 1000\times 9.8)$

$={10}^5+{10}^6\times 9.8$

$={10}^5+98\times {10}^5$

$=9.9\times {10}^{6}Pa$

Thus, It is the normal stress that the baloon will be subjected to under the depth of 1 km in water.