Answer :
Final answer:
Freefall is falling under gravity, weightlessness is freefall feeling no weight, a dam is wider at the bottom to distribute pressure, swimming is easier in the sea due to buoyancy.
Explanation:
Freefall is when an object falls only under the influence of gravity, experiencing an acceleration due to gravity. In weightlessness, an object is in freefall but also experiences a sensation of zero weight due to being in a state of continuous freefall around a planet or celestial body.
The wall of a dam is wider at the bottom to withstand the pressure exerted by the water it holds. The wider base distributes the force over a larger area, reducing the pressure at any specific point on the dam.
It is easier to swim in the sea than in a river because the sea has higher buoyancy due to its salt content which makes it easier for a person to float and swim. In contrast, fresh river water has lower buoyancy.
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