HESI A2 Physics Practice Test

Correct Answer: D

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: B

Rationale: The correct answer is B: Boundary layer separation. When a fluid encounters a bluff body, such as a car, the flow separates behind the object due to pressure differences, creating a region of low pressure. This separation of the boundary layer results in increased drag on the object. Cavitation (A) is the formation of vapor bubbles due to low pressure, not specific to bluff bodies. The Bernoulli effect (C) refers to the relationship between fluid speed and pressure, not directly related to flow separation. Drag crisis (D) is a sudden decrease in drag experienced by an object at high speeds, not directly related to flow separation behind a bluff body.

Correct Answer: B

Rationale: The correct answer is B: Cork. Density is mass per unit volume. Cork is the lightest material among the choices due to its low mass and high volume, resulting in the lowest density. Water (A) has a higher density than cork. Aluminum (C) and steel (D) are metals with higher densities than cork due to their higher mass and lower volume. Cork's low density makes it less dense compared to the other materials.

Correct Answer: D

Rationale: The correct answer is D: Refraction. Refraction is the phenomenon of light bending as it passes through different mediums, such as a prism. This occurs due to the change in speed of light when transitioning from one medium to another, causing the light to change direction. Reflection (A) is the bouncing back of light off a surface, not bending. Electrical conduction (B) is the movement of electric charges through a material, not related to light behavior. Diffraction (C) is the bending of light around obstacles or through small openings, not specifically related to prisms.

Correct Answer: A

Rationale: The correct answer is A: 0 watts. When an appliance draws 0 amperes, it means no current flows, so no power is consumed. Power (in watts) is calculated as Voltage x Current. Since the current is 0, the power consumed is 0 watts. Choice B, C, and D are incorrect because they assume there is power consumption when there is no current flowing.