HESI A2 Physics

Correct Answer: A

Rationale: To calculate the magnitude of the resulting force, we use Coulomb's Law: F = k * |q1 * q2| / r^2, where k is the electrostatic constant (8.99 x 10^9 N m^2/C^2), q1 and q2 are the charges, and r is the distance between them. Plugging in the values: F = (8.99 x 10^9) * |4 x 10^-6 * 2 x 10^-6| / 1^2 = 0.072 N. However, the question asks for the magnitude, so the answer should be 0.072 N, which corresponds to choice B. The other choices are incorrect because they do not correctly calculate the force using Coulomb's Law or misinterpret the question.

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: To find amperes, use the formula: Power (W) = Voltage (V) x Current (I) Given: P = 1525W, V = 110V Therefore, I = P / V = 1525W / 110V = 13.8636A ≈ 13.9 amperes (option D). Explanation: The correct answer is D because it correctly calculates the amperes drawn by the hair dryer using the power and voltage values provided. Option A is too high, B and C are too low.

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: C

Rationale: Rationale: 1. Speed of sound in a fluid depends on its bulk modulus, which measures the fluid's resistance to compression. 2. Density affects how closely packed the molecules are, influencing the speed of sound propagation. 3. Viscosity and surface tension do not directly affect the speed of sound in a fluid. 4. Choice C is correct as both density and bulk modulus are crucial factors in determining the speed of sound in a compressible fluid.