HESI A2 Physics

Correct Answer: D

Rationale: To calculate work, we use the formula W = F*d, where W is work, F is force, and d is distance. In this case, the force is 15 N and the distance is 3 m. So, W = 15 N * 3 m = 45 N⋅m. Therefore, the correct answer is D. Choice A is incorrect as it incorrectly calculates work by dividing force by distance. Choice B is incorrect as it only provides the correct unit for work, not the actual calculation. Choice C is incorrect as it incorrectly multiplies force and distance to get the wrong result.

Correct Answer: D

Rationale: The correct answer is D: Strongly repulsive. When two identical positively charged spheres are brought close together, they will experience a strong repulsive force due to like charges repelling each other based on Coulomb's Law. The force between them is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. The repulsive force will increase as the spheres get closer, leading to a strong repulsion. Choices A and C are incorrect because like charges do not attract each other. Choice B is incorrect as the spheres will experience a repulsive force, not a zero force.

Correct Answer: C

Rationale: Step 1: A negative heat of reaction indicates that energy is released during the reaction. Step 2: Since energy is released, the products have lower energy compared to the reactants. Step 3: Lower energy in products means they are more stable. Therefore, the correct answer is C: The products have less energy and are more stable. Summary: A: Incorrect. Products have lower energy and are more stable, not less stable. B: Incorrect. Products have lower energy and are more stable, not more stable. D: Incorrect. Products have lower energy and are more stable, not less stable.

Correct Answer: A

Rationale: The correct answer is A: Pressure. Pumps increase fluid pressure by adding energy to the fluid. When the fluid flows through the pump, it gains kinetic energy which is then converted into pressure energy. Choice B is incorrect because pumps do not primarily aim to increase velocity only. Choice C is incorrect as while pumps do increase both pressure and velocity, the primary goal is to increase pressure. Choice D is incorrect as pumps are specifically designed to increase either pressure, velocity, or both, depending on the application.

Correct Answer: A

Rationale: In an adiabatic process, there is no heat transfer between the system and the surroundings (choice A is correct). This is because adiabatic processes occur without any heat exchange, so the heat transfer (Q) is zero. The other choices are incorrect because in an adiabatic process, there is no requirement for constant temperature (choice B), constant pressure (choice C), or no change in internal energy (choice D). Adiabatic processes focus on the absence of heat transfer, not necessarily on the maintenance of specific temperature, pressure, or energy conditions.