HESI A2 Physics Practice Test

Correct Answer: C

Rationale: The gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them (F = G * (m1 * m2) / r^2). When the distance is halved, the force quadruples (2^2 = 4 times). Therefore, if the original force is 12 units, when the distance is halved, the new force will be 12 * 4 = 48 units. Therefore, the correct answer is C. Choice A (3 units) is incorrect because the force increases when the distance is halved. Choice B (6 units) is incorrect as well, as the force should increase more when the distance is halved. Choice D (48 units) is incorrect because the new force of attraction is not doubled but quadrupled when the distance is halved.

Correct Answer: B

Rationale: The correct answer is B because fluid dynamics specifically focuses on the motion and behavior of fluids under various conditions. It deals with how fluids move, interact, and change in response to forces. Choice A (Fluid Statics) is incorrect because it pertains to fluids at rest, not in motion. Choice C (Phase transitions) is incorrect as it relates to changes in state, not fluid motion. Choice D (Engineering applications) is too broad, encompassing various aspects beyond just fluid dynamics. Fluid dynamics uniquely studies fluid flow, making choice B the correct option.

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.

Correct Answer: D

Rationale: The correct answer is D (5 feet). When Jack stands 5 feet away from the mirror, his image will appear the same distance behind the mirror. This is because the distance between Jack and his image in the mirror is equal to the distance between Jack and the mirror itself. Therefore, the image of Jack will also be 5 feet away from him. Choice A (2.5 feet) is incorrect because the image distance is equal to the object distance in a plane mirror. Choice B (3 feet) is incorrect as it does not follow the principle of image formation in a plane mirror. Choice C (4.5 feet) is incorrect as the image distance is always equal to the object distance in a plane mirror.