HESI A2 Physics

Correct Answer: B

Rationale: The correct answer is B: Conduction. When the hot cup of coffee is placed on a cold table, heat transfer primarily occurs through conduction. This is because heat is transferred from the hot coffee to the cold table through direct contact. Conduction is the process of heat transfer through a material due to direct molecular collisions. Radiation (choice A) involves the transfer of heat through electromagnetic waves, which is not the primary process in this scenario. Convection within the coffee (choice C) involves the transfer of heat through the movement of fluid particles, but in this case, the primary heat transfer mechanism is conduction. Choice D is incorrect as it suggests a combination of conduction and convection, when conduction is the dominant process in this situation.

Correct Answer: C

Rationale: During adiabatic compression, no heat is exchanged with the surroundings, so the internal energy of the gas is increased, leading to an increase in temperature (Choice C). Adiabatic compression is an inherently exothermic process due to the work done on the gas. Choice A is incorrect because temperature is directly related to the internal energy of the gas, not heat exchange. Choice B is incorrect as compression of a gas leads to an increase in temperature, not a decrease. Choice D is incorrect as the behavior of a gas during adiabatic compression can be predicted based on the laws of thermodynamics.

Correct Answer: B

Rationale: The correct answer is B: Conduction. When the hot cup of coffee is placed on a cold table, heat transfer primarily occurs through conduction. This is because heat is transferred from the hot coffee to the cold table through direct contact. Conduction is the process of heat transfer through a material due to direct molecular collisions. Radiation (choice A) involves the transfer of heat through electromagnetic waves, which is not the primary process in this scenario. Convection within the coffee (choice C) involves the transfer of heat through the movement of fluid particles, but in this case, the primary heat transfer mechanism is conduction. Choice D is incorrect as it suggests a combination of conduction and convection, when conduction is the dominant process in this situation.

Correct Answer: D

Rationale: The correct answer is D. Displacement is the change in position from the starting point to the endpoint, regardless of the path taken. In this case, traveling 500 miles northeast and then 500 miles southwest cancels out the movement, resulting in a displacement of 0 miles. However, the distance traveled is the total distance covered, which is 1,000 miles in this case. Therefore, option D correctly states that the displacement is 0 miles, and the distance traveled is 1,000 miles. Option A is incorrect because the distance traveled is not 0 miles. Option B is incorrect as the displacement is 0 miles. Option C is incorrect as both displacement and distance traveled are not 0 miles.

Correct Answer: A

Rationale: The correct answer is A because laminar flow is characterized by smooth, parallel layers of fluid particles moving in a uniform manner without mixing. This flow pattern occurs at low Reynolds numbers, where viscous forces dominate over inertial forces. Option B is incorrect as it describes turbulent flow, which is characterized by erratic and chaotic motion. Option C is incorrect because high viscosity would lead to more laminar flow, not hinder it. Option D is incorrect as incompressibility is a property of fluids and does not specifically characterize laminar flow.