HESI A2 Physics Quizlet

Correct Answer: A

Rationale: To calculate density, divide the mass by the volume. In this case, 24 g / 6 cm3 = 4 g/cm3. This is the correct answer (A) because density is expressed in units of mass per volume. Choice B is incorrect as it has the inverse units. Choices C and D are incorrect as they do not match the calculated value based on the given mass and volume.

Correct Answer: B

Rationale: The correct answer is B: Ketchup. Ketchup is a common example of a shear-thinning fluid because its viscosity decreases under shear stress. When force is applied to ketchup, its resistance decreases, making it easier to flow. This behavior is characteristic of shear-thinning fluids, where viscosity decreases with increasing shear rate. Water (Choice A) is a Newtonian fluid with constant viscosity, while Air (Choice C) and Alcohol (Choice D) do not exhibit shear-thinning behavior. Therefore, B is the correct choice.

Correct Answer: A

Rationale: To find the object's velocity, we use the formula for momentum: momentum = mass x velocity. Given momentum = 180 kg⋅m/s and mass = 45 kg, we rearrange the formula to solve for velocity: velocity = momentum / mass. Substituting the values, velocity = 180 kg⋅m/s / 45 kg = 4 m/s. Therefore, the correct answer is A: 4 m/s. Summary: B: 8.1 km/s and C: 17.4 km/h are incorrect as they do not match the calculated velocity of 4 m/s. D: 135 m/s is incorrect as it is significantly higher than the calculated velocity of 4 m/s.

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: B

Rationale: The correct answer is B: ṁ = ρvA. This equation is derived from the continuity equation, which states that mass flow rate ṁ remains constant in steady flow. Mass flow rate ṁ is the product of fluid density ρ, cross-sectional area A, and average velocity v. This relationship is crucial for understanding the behavior of fluids in pipes. Choice A is incorrect because the mass flow rate can be determined using the given equation without any additional information. Choice C is incorrect because Bernoulli's principle is not directly related to the calculation of mass flow rate. Choice D is incorrect because the equation of state for the specific fluid is not required to determine the mass flow rate using the continuity equation.