HESI Exams Quizlet Physics

Correct Answer: B

Rationale: The drag force experienced by an object moving through a fluid depends on fluid properties (like viscosity and density) and object velocity. This is because the resistance encountered by the object is influenced by how easily the fluid can flow around it and the speed at which it moves through the fluid. The shape and size of the object can affect the drag force, but they are not the only factors determining it. The depth of submersion primarily affects buoyancy, not drag force. The buoyant force acting on the object is related to its weight and the density of the fluid, but it does not directly determine the drag force experienced by the object.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Archimedes' principle states that the buoyant force on an object is equal to the weight of the fluid displaced. 2. Submarines adjust their buoyancy by changing the amount of water they displace, allowing them to submerge or resurface. 3. This control of buoyancy is crucial for submarines to navigate underwater efficiently while conserving energy. 4. Choice A is incorrect as density differences affect buoyancy, not causing objects to sink regardless. 5. Choice B is incorrect as airplane lift is generated by the Bernoulli principle and wing design, not Archimedes' principle. 6. Choice D is incorrect as helium balloons float due to buoyancy force exceeding their weight, not overcoming gravity.

Correct Answer: D

Rationale: The correct answer is D: Dry ice. Dry ice is solid carbon dioxide that sublimes directly into carbon dioxide gas without melting into a liquid state. This process can be observed in everyday situations, such as when dry ice "evaporates" in a cooler. Iron (A) and Silver (B) do not undergo sublimation but instead melt into liquid phases. Salt crystal (C) also melts into a liquid (brine solution) before evaporating.

Correct Answer: D

Rationale: The resistance of a wire is inversely proportional to its cross-sectional area. Smaller diameter wires have higher resistance. As the wire gauge number decreases, the diameter increases. Therefore, wire gauge 4 with the smallest diameter (5.19 mm) would have the greatest resistance among the given choices. Choices A, B, and C have larger diameters, so their resistances would be lower compared to choice D.

Correct Answer: B

Rationale: The correct answer is B (15.625 cm). To calculate the image height using mirror formula (1/f = 1/v + 1/u), first find the object distance (u) which is -20 cm (since object is placed on the same side as focal point, it is negative). Then, solve for image distance (v) by substituting u and f values. Next, use magnification formula (m = -v/u) to find the magnification factor. Finally, multiply the object height by the magnification factor to get the image height, which is 15.625 cm. Choice A (30.5 cm) is incorrect as it is double the correct answer. Choice C (-15 cm) and choice D (-30.5 cm) are incorrect as the negative sign indicates an inverted image, but in this case, the image is upright.