HESI A2 Physics Practice Test

Correct Answer: A

Rationale: Rationale: 1. Atoms are electrically neutral, meaning they have no overall charge. 2. Electrons are negatively charged, and protons are positively charged. 3. In a neutral atom, the number of protons equals the number of electrons to balance charges. 4. Therefore, in an electrically neutral atom, the number of electrons is equal to the number of protons (Choice A). Summary: - Choice B is incorrect because protons are not always equal to neutrons in an atom. - Choice C is incorrect as the number of neutrons can vary and is not always greater than protons. - Choice D is incorrect as electrons can be equal to or greater than protons in an atom, depending on the element.

Correct Answer: D

Rationale: To calculate acceleration, you must use the formula: acceleration = change in velocity / change in time. This is because acceleration is the rate of change of velocity with respect to time. By dividing the change in velocity by the change in time, you get the acceleration of the object. This formula is derived from the definition of acceleration as the rate of change of velocity. The other choices are incorrect because they do not follow the fundamental concept of acceleration as the change in velocity over time. Choice A incorrectly suggests dividing time by velocity, choice B incorrectly suggests multiplying velocity by time, and choice C incorrectly suggests finding the difference between time and velocity, none of which accurately calculate acceleration.

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: A

Rationale: Failed to generate a rationale after 5 retries.

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.