HESI Exams Quizlet Physics

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: B

Rationale: The correct answer is B (15.625 cm). To calculate the image height using mirror formula (1/f = 1/v + 1/u), first find the object distance (u) which is -20 cm (since object is placed on the same side as focal point, it is negative). Then, solve for image distance (v) by substituting u and f values. Next, use magnification formula (m = -v/u) to find the magnification factor. Finally, multiply the object height by the magnification factor to get the image height, which is 15.625 cm. Choice A (30.5 cm) is incorrect as it is double the correct answer. Choice C (-15 cm) and choice D (-30.5 cm) are incorrect as the negative sign indicates an inverted image, but in this case, the image is upright.

Correct Answer: A

Rationale: Conduction is the transfer of heat through a material without any movement of the material itself. In contrast, convection involves the movement of fluids to transfer heat, radiation transfers heat through electromagnetic waves, and isothermalization is not a recognized mode of heat transfer. Therefore, the correct answer is A because it does not involve the movement of material or fluid to transfer heat like convection does. Convection, radiation, and isothermalization are all modes of heat transfer, making them incorrect choices.

Correct Answer: D

Rationale: The primary factor responsible for generating lift on an airplane wing is the application of Bernoulli's principle to the airfoil's shape. As the air flows over the curved upper surface of the wing, it speeds up, creating lower pressure according to Bernoulli's principle. This pressure difference between the upper and lower surfaces generates lift. This phenomenon is crucial for flight and is the fundamental principle behind how wings work. A: Propulsion force generated by the engines is not directly related to lift generation but rather to providing thrust for forward motion. B: Buoyant forces acting on the entire aircraft are relevant for lighter-than-air aircraft like hot air balloons, not for airplanes. C: Drag reduction achieved through streamlining is important for reducing air resistance but not the primary factor for lift generation on a wing.

Correct Answer: B

Rationale: In an isobaric process (constant pressure), work done is given by W = PΔV. Since the pressure is constant, work done is directly proportional to the volume change. As volume increases, work is done by the system, making it positive. If volume decreases, work is done on the system, making it negative. Choice A is incorrect as work is done even if volume change is zero. Choice C is incorrect as work's sign depends on the direction of volume change. Choice D is incorrect as work done is indeed dependent on pressure and volume change in an isobaric process.