HESI A2 Physics Quizlet

Correct Answer: B

Rationale: The correct answer is B: Decreases. When light travels from air into a denser medium like glass, it slows down due to the higher refractive index of the denser medium. This change in speed causes the light to bend or refract towards the normal line, demonstrating the phenomenon of refraction. The other choices are incorrect because light does not speed up when entering a denser medium (choice A), its speed is not constant (choice C), and it does not become unpredictable (choice D) - it follows the laws of physics governing refraction.

Correct Answer: D

Rationale: To compress the spring from 40 cm to 30 cm, we calculate the change in length = 40 cm - 30 cm = 10 cm = 0.1 m. The force needed is given by Hooke's Law: F = k * x, where F is the force, k is the spring constant (20 N/m), and x is the change in length (0.1 m). Therefore, F = 20 N/m * 0.1 m = 2 N. Choice D (2 N) is correct because it correctly applies Hooke's Law. Choices A, B, and C are incorrect because they do not correctly calculate the force based on the given spring constant and change in length.

Correct Answer: A

Rationale: The correct answer is A because the second law of thermodynamics states that the total entropy of an isolated system always increases over time in a spontaneous process. This increase in entropy signifies an increase in disorder and randomness within the system and its surroundings. Therefore, choice A is correct as it aligns with the fundamental principle of entropy and the second law of thermodynamics. Choices B, C, and D are incorrect as they contradict this law by suggesting a decrease in total entropy, constancy of entropy, or a decrease in system entropy, respectively.

Correct Answer: C

Rationale: To calculate current, we use the formula I = P/V, where P is power in watts and V is voltage in volts. In this case, the power is 780 watts and the voltage is 120 volts. Therefore, I = 780/120 = 6.5 amperes. Choice C is correct. Choice A (660 amperes) is incorrect as it is an unrealistic and excessively high value for current in this scenario. Choice B (150 amperes) is incorrect as it does not align with the calculated value using the formula. Choice D (0.15 amperes) is incorrect as it is the decimal form of the correct answer but not expressed in amperes.

Correct Answer: B

Rationale: The correct answer is B, the highest peak. At the highest peak, the car has the greatest height above the ground, resulting in the greatest potential energy due to gravity. Potential energy is directly proportional to the height of an object above the reference point. As the car descends from the peak, potential energy is converted to kinetic energy. Choices A, C, and D are incorrect because potential energy is not solely determined by the start or end of the ride, nor the lowest point on the roller coaster.