Using Laplace law for spherical bubble, the pressure difference P'- P = 4T/r where T = surface tension and r = radius of sphere.
Now, the pressure difference on the hollow sphere P' - P = dgh where d = density of liquid, g = acceleration due to gravity and h = maximum depth to which sphere must be immersed.
When someone is struct by lightning, the electricity passes through the body, into the earth. Here, our body acts as a lightning conductor to complete the earthing process.
