HESI A2 Physics Practice Test

Correct Answer: A

Rationale: Rationale: An ideal fluid exhibits zero shear stress at any strain rate. This is because an ideal fluid is assumed to have no resistance to flow, resulting in no shear stress being generated regardless of the strain rate. This is a fundamental characteristic of an ideal fluid and distinguishes it from real fluids that exhibit varying levels of shear stress. Summary: - Choice A is correct as an ideal fluid exhibits zero shear stress at any strain rate. - Choice B is incorrect as it describes a Newtonian fluid which has a linear relationship between shear stress and strain rate. - Choice C is incorrect as it describes a Non-Newtonian fluid with a non-linear relationship between shear stress and strain rate. - Choice D is incorrect as it describes the temperature dependence of viscosity, which is not a defining characteristic of an ideal fluid.

Correct Answer: C

Rationale: The correct answer is C because in shear thickening behavior, the fluid's viscosity increases with increasing shear rate. As more force is applied, the fluid's particles align in a way that increases resistance to flow, leading to higher viscosity. Choices A and B are incorrect because shear thickening involves a change in viscosity with shear rate. Choice D is incorrect as viscosity in non-Newtonian fluids is influenced by shear rate, not just applied pressure.

Correct Answer: C

Rationale: To calculate kinetic energy, we use the formula KE = 0.5 * mass * velocity^2. Plugging in the values (0.5 * 500 kg * (10 m/s)^2), we get 0.5 * 500 * 100 = 25000 J. Therefore, the correct answer is C (2.5 * 10^4 J). Choice A (50 J) is incorrect as it is too low. Choice B (250 J) is incorrect, as it only considers the mass without accounting for the velocity. Choice D (5.0 * 10^5 J) is incorrect as it overestimates the kinetic energy due to incorrect calculations.

Correct Answer: A

Rationale: Coulomb's law relates to electrostatic interaction. It describes the force between two charged objects based on their charges and the distance between them. It is mathematically represented as F = k*q1*q2/r^2, where F is the force, k is the Coulomb constant, q1 and q2 are the charges, and r is the distance between the charges. This law is fundamental in understanding and calculating the behavior of electrically charged particles. Summary: B: Rigid body motion - unrelated to Coulomb's law. C: Heat conduction - unrelated to Coulomb's law. D: Universal gravitation - Coulomb's law is specific to electric charges, not gravitational forces.

Correct Answer: B

Rationale: The correct answer is B: The ratio of the potential difference between the ends of a conductor to current is a constant, R. This is in accordance with Ohm's law, which states that V (voltage) = I (current) x R (resistance). Ohm's law establishes a direct proportionality between voltage and current when resistance is constant. The constant R represents the resistance of the conductor. Option A is incorrect because voltage and current are directly proportional when resistance is constant, not inversely proportional. Option C is incorrect as voltage is not the amount of charge passing through a point per second, but rather the potential difference. Option D is incorrect as power is calculated using the formula P = VI, not I x V.