HESI A2 Physics Quizlet

Correct Answer: A

Rationale: As the frequency of a sound wave increases, its wavelength decreases because the speed of sound remains constant in a given medium. This is described by the formula speed = frequency x wavelength. Therefore, when frequency increases, wavelength must decrease to maintain a constant speed. Summary: Choice A is correct because frequency and wavelength are inversely proportional. Choices B, C, and D are incorrect as they do not follow the relationship between frequency and wavelength in a sound wave.

Correct Answer: A

Rationale: The correct answer is A, P = ρgh. This is derived from the hydrostatic equation, which states that pressure in a static fluid at a depth h is directly proportional to the density of the fluid (ρ), gravitational acceleration (g), and depth (h). Therefore, P = ρgh is the correct formula to calculate pressure in a static fluid. Choice B, P = γh, does not include the density of the fluid and is incorrect. Choice C, P = μgh, introduces a new variable μ which is not part of the hydrostatic equation and is thus incorrect. Choice D, P = bh, does not include the density of the fluid or gravitational acceleration, making it an incorrect formula for calculating pressure in a static fluid.

Correct Answer: A

Rationale: The correct answer is A because density is calculated by dividing mass by volume. For block A, density = 6.5g/16.25cm3 = 0.4 g/cm3. To determine the density of other blocks: B = 80g/32cm3 = 2.5 g/cm3, C = 48g/22cm3 = 2.18 g/cm3, D = 100g/250cm3 = 0.4 g/cm3. Since block A and D have the same density of 0.4 g/cm3, block A is the correct answer. Block B and C have higher densities, so they are incorrect choices.

Correct Answer: D

Rationale: The correct answer is D: ∫ dQ/T ≤ 0. This is based on the Clausius inequality which states that for a cyclic process involving heat transfer at a constant temperature T, the integral of dQ/T must be less than or equal to zero. This inequality arises from the second law of thermodynamics, specifically stating that heat cannot spontaneously flow from a colder body to a hotter body. If the integral were greater than zero, it would imply a violation of this principle. The other choices are incorrect because they do not accurately represent the Clausius inequality or the relationship between heat transfer and temperature in a cyclic process. Choice A is incorrect as there is indeed a relationship between heat transfer and temperature. Choice B is incorrect as it should be ≤ 0, not ≥ 0. Choice C is incorrect as the integral of Q/T should not be constant for a cyclic process.

Correct Answer: D

Rationale: To calculate power, we use the formula P = W / t, where P is power, W is work done, and t is time taken. The correct formula is D: P = F / t. Power is the rate at which work is done, so it is the work done per unit time. Therefore, the correct formula depicts power as the force applied divided by the time taken to do the work. Incorrect choices: A: P = W / F - This formula is incorrect because power is not work divided by force. B: P = d / t - This formula is incorrect because power is not distance divided by time. C: P = W x t - This formula is incorrect because power is not work multiplied by time. In summary, choice D is correct because power is defined as work done per unit time, which is represented by force divided by time.