HESI A2 Physics Quizlet

Correct Answer: B

Rationale: To find the object distance, we can use the mirror formula: 1/f = 1/di + 1/do. Given f=2 cm, di=6 cm, we can solve for do. Plugging in the values, we get 1/2 = 1/6 + 1/do. Solving for do, we get do=6 cm. Therefore, the correct answer is B (6 cm). Choice A (3 cm) is incorrect because it does not satisfy the mirror formula equation. Choice C (12 cm) and D (30 cm) are also incorrect as they do not correspond to the calculated object distance of 6 cm.

Correct Answer: A

Rationale: To find the object's velocity, we use the formula for momentum: momentum = mass x velocity. Given momentum = 180 kg⋅m/s and mass = 45 kg, we rearrange the formula to solve for velocity: velocity = momentum / mass. Substituting the values, velocity = 180 kg⋅m/s / 45 kg = 4 m/s. Therefore, the correct answer is A: 4 m/s. Summary: B: 8.1 km/s and C: 17.4 km/h are incorrect as they do not match the calculated velocity of 4 m/s. D: 135 m/s is incorrect as it is significantly higher than the calculated velocity of 4 m/s.

Correct Answer: A

Rationale: As the frequency of a sound wave increases, its wavelength decreases because the speed of sound remains constant in a given medium. This is described by the formula speed = frequency x wavelength. Therefore, when frequency increases, wavelength must decrease to maintain a constant speed. Summary: Choice A is correct because frequency and wavelength are inversely proportional. Choices B, C, and D are incorrect as they do not follow the relationship between frequency and wavelength in a sound wave.

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: D

Rationale: The correct answer is D: attraction. According to the right-hand rule for magnetic fields, when two long, parallel wires carry currents in the same direction, the magnetic fields produced by the currents will interact in a way that causes the wires to attract each other. This is because the magnetic field lines around each wire will form concentric circles and intersect with each other, leading to an attractive force between the wires. Choices A, B, and C are incorrect because the force between the wires in this scenario is not unpredictable, repulsion, or nonexistent; it is specifically an attractive force due to the interaction of the magnetic fields produced by the currents in the wires.