A current meter weighs 50 lbs submerged. If a lift bag is used to make it neutral, what is the surface volume of air added?

To determine the surface volume of air added to make a current meter that weighs 50 lbs submerged neutrally buoyant, it is essential to apply the principles of buoyancy and the characteristics of lift bags.

When an object is submerged in water, it displaces a volume of water equivalent to its submerged weight. In this case, a current meter weighing 50 lbs submerged needs to be neutralized. To achieve neutral buoyancy, you must add enough buoyant force, provided by a lift bag, to counteract the weight of the object.

The key relationship involves understanding Archimedes' principle, which states that the buoyant force acting on a submerged object is equal to the weight of the fluid displaced by that object. The volume of air added from the lift bag must create a buoyant force equal to the weight of the current meter, which is 50 lbs.

The lift bag operates on the principle that at the surface, 1 cubic foot of air provides buoyancy sufficient to lift approximately 62.4 lbs of water (the approximate weight of one cubic foot of fresh water). Therefore, to find the volume of air needed to lift a 50 lbs submerged object, you can calculate the volume as follows:

1. Take