Answer:
It is measuring the Buoyant Force.
Step-by-step explanation:
A spring scale shows the water-filled bottle to weigh approximately 6N in air, and nearly 0N (Zero N) when it is fully submerged in a large container of water. Since gravity is still acting on the bottle when it is submerged in the water, there must be a force of 6N pushing up on it. This is the buoyant force.
