HESI A2 Physics

Correct Answer: C

Rationale: To find the image distance using the mirror formula (1/f = 1/v + 1/u), we first need to calculate the object distance (u). Given the object distance (u) is 20 cm, and the focal length (f) is 10 cm, we can substitute these values into the formula to find the image distance (v). Solving for v, we get v = 60 cm. Therefore, the correct answer is C: 60 cm. Choice A (20 cm) is incorrect as the image distance is not equal to the object distance when using a concave mirror. Choice B (40 cm) is incorrect as it does not account for the focal length of the mirror. Choice D (75 cm) is incorrect as it is not the result of the correct calculation using the mirror formula.

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: D

Rationale: To find the total voltage in a series circuit, you add the voltages of each battery. In this case, with four 5 V batteries connected in series, the total voltage would be 5 V + 5 V + 5 V + 5 V = 20 V. Therefore, the correct answer is D. Choice A (5.0 V) is incorrect because that would be the voltage of just one battery, not the total voltage of the circuit. Choice B (10.0 V) is incorrect as well since it represents the total voltage of two batteries, not four. Choice C (15.0 V) is also incorrect as it would be the total voltage of three batteries, not four.

Correct Answer: C

Rationale: The correct answer is C because in a cyclic process, the system returns to its initial state, so the net work done over the entire cycle can be positive, negative, or zero depending on the path taken. If the system undergoes a clockwise cycle on a PV diagram, work is done by the system (positive Wnet). If the cycle is counterclockwise, work is done on the system (negative Wnet). If the cycle is a closed loop, the net work done can be zero. Choices A and B are incorrect because they are too absolute and do not consider the different possibilities in a cyclic process. Choice D is incorrect because the net work done is not necessarily equal to the total heat transferred; it depends on the specific process and path taken.

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.