NICET - Highway Construction Inspection Practice Exam

If a block weighs 300 pounds in air and is submerged in water, which formula calculates its submerged weight?

1. W(submerged) = Weight in Air - Buoyant Force

2. W(submerged) = Weight in Air + Buoyant Force

3. W(submerged) = Buoyant Force - Weight in Air

4. W(submerged) = Weight Density x Volume

The correct answer is: W(submerged) = Weight in Air - Buoyant Force

To determine the submerged weight of an object, it’s essential to understand the concept of buoyancy and how it affects the weight of an object when it is submerged in a fluid, such as water. When an object is submerged, it experiences an upward force called the buoyant force, which counteracts its weight in air. The correct calculation for submerged weight is derived from the relationship of these forces. The weight of the object in air is the total force acting downward, while the buoyant force acts upward. Therefore, to find the weight of the object when submerged, one must subtract the buoyant force from the weight in air. This accounts for the reduction in effective weight due to the upward force exerted by the fluid. Using the given information, if a block weighs 300 pounds in air, the weight observed while it is submerged will be less than 300 pounds by the amount of the buoyant force acting on it. This is accurately represented by the formula: W(submerged) = Weight in Air - Buoyant Force. This interpretation aligns with Archimedes' principle, which states that an object submerged in fluid experiences a loss in weight equal to the weight of the fluid displaced. This ensures that the submerged weight reflects the actual