HESI A2 Physics

Correct Answer: C

Rationale: The correct answer is C because psychrometrics specifically deals with the properties of mixtures of moist air and water vapor. It focuses on the study of air-water vapor mixtures and their interactions, such as humidity, temperature, and moisture content. Choice A (Ideal gases) is incorrect because psychrometrics goes beyond the behavior of ideal gases. Choice B (Magnetic materials) is incorrect as it is unrelated to the study of air-water vapor mixtures. Choice D (Nuclear reactions) is also incorrect as it pertains to nuclear physics, not the properties of air-water vapor mixtures. In summary, the correct answer C aligns with the specific focus of psychrometrics on moist air and water vapor properties, making it the most appropriate choice.

Correct Answer: C

Rationale: The correct answer is C (24 units). When you double the mass of both objects, the gravitational force between them increases by a factor of 4 (2 times 2). Therefore, the new force of attraction would be 12 units x 4 = 24 units. Choice A (3 units) and B (6 units) are incorrect because they do not account for the increase in mass. Choice D (48 units) is incorrect as it overestimates the effect of doubling the mass on the gravitational force.

Correct Answer: A

Rationale: The correct answer is A: Hertz. Frequency is the number of cycles per second in an alternating current (AC). Hertz is the unit used to measure frequency. It represents the number of times the current changes direction in one second. Amperes (B) measure current, Volts (C) measure voltage, and Ohms (D) measure resistance, which are not related to the frequency of an AC current.

Correct Answer: C

Rationale: Rationale: 1. Speed of sound in a fluid depends on its bulk modulus, which measures the fluid's resistance to compression. 2. Density affects how closely packed the molecules are, influencing the speed of sound propagation. 3. Viscosity and surface tension do not directly affect the speed of sound in a fluid. 4. Choice C is correct as both density and bulk modulus are crucial factors in determining the speed of sound in a compressible fluid.

Correct Answer: D

Rationale: The correct answer is D because salt increases the density of water, making it more buoyant. Higher water density provides greater buoyant force on the boat, allowing it to float more easily. Choices A, B, and C are incorrect as salt does not directly affect the mass of the boat, the volume of water, or the density of the boat itself.