HESI Exams Quizlet Physics

Correct Answer: A

Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. In this case, for option A, the momentum of the car is calculated as 1,250 kg x 5 m/s = 6,250 kg*m/s. This is greater than the momentum of the other choices. For option B, the momentum of the person is 80 kg x 4 m/s = 320 kg*m/s, which is less than the car's momentum. For option C, the momentum of the meteorite is 10 kg x 600 m/s = 6,000 kg*m/s, which is also less than the car's momentum. For option D, the momentum of the rock is 0.5 kg x 40 m/s = 20 kg*m/s, making it the smallest momentum among the choices. Therefore, the car moving at 5 m/s has the greatest momentum due to its higher mass and velocity compared to the other objects.

Correct Answer: C

Rationale: When a charged particle moves through a vacuum at a constant speed, it generates both an electric and magnetic field. This phenomenon is described by Maxwell's equations in electromagnetism. The moving charge creates a changing electric field which, in turn, induces a magnetic field according to Faraday's law of electromagnetic induction. This interplay between electric and magnetic fields is fundamental to electromagnetism. Choice A is incorrect as the moving charge does not only generate an electric field. Choice B is incorrect because the moving charge does not only generate a magnetic field. Choice D is incorrect because a moving charged particle always generates both electric and magnetic fields due to the fundamental principles of electromagnetism.

Correct Answer: C

Rationale: The correct answer is C because reversible processes can be run in both directions with the same outcome, while irreversible processes cannot. In a reversible process, the system and surroundings can be restored to their original states after the process is reversed, maintaining equilibrium. This is not possible in irreversible processes, where energy dissipation and entropy generation lead to permanent changes. Choices A, B, and D are incorrect because reversible processes can involve heat transfer, do take time, and do not violate the first law of thermodynamics.

Correct Answer: D

Rationale: The resistance of a wire is inversely proportional to its cross-sectional area. Smaller diameter wires have higher resistance. As the wire gauge number decreases, the diameter increases. Therefore, wire gauge 4 with the smallest diameter (5.19 mm) would have the greatest resistance among the given choices. Choices A, B, and C have larger diameters, so their resistances would be lower compared to choice D.

Correct Answer: C

Rationale: Potential energy increases as particles approach each other because the distance between them decreases, leading to an increase in repulsive forces due to the close proximity of the particles. This causes the potential energy to rise as the particles try to move away from each other to reduce the repulsive forces. Attractive forces do not increase in this scenario, and in fact, they may decrease due to the particles being closer together. Repulsive forces increase as the particles get closer, not decrease. Therefore, the correct answer is C.