HESI A2 Physics

Correct Answer: D

Rationale: The correct answer is D because salt increases the density of water, making it more buoyant. Higher water density provides greater buoyant force on the boat, allowing it to float more easily. Choices A, B, and C are incorrect as salt does not directly affect the mass of the boat, the volume of water, or the density of the boat itself.

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: A

Rationale: The correct answer is A: Experience a net buoyant force acting upwards. When the specific gravity of an object is greater than 1, it means the object is denser than the reference fluid. According to Archimedes' Principle, a submerged object experiences an upward buoyant force equal to the weight of the fluid it displaces. Since the object is denser than the fluid, it will displace less fluid, resulting in a net buoyant force acting upwards. Choice B is incorrect because a denser object will displace less fluid, leading to an upward buoyant force. Choice C is incorrect because neutrally buoyant objects have an SG equal to that of the reference fluid. Choice D is incorrect because the object's volume is not needed to determine the direction of the buoyant force based on specific gravity alone.

Correct Answer: B

Rationale: To find the radius of the circular track, we use the formula: circumference = 2 * π * radius. Given circumference = 2,500m, we can rearrange the formula to solve for radius: radius = circumference / (2 * π) = 2,500 / (2 * 3.14) ≈ 398.73m. Therefore, the closest option to the calculated radius is B: 400m. Incorrect answers: A: 1,000m - This is twice the correct radius, not accurate. C: 25m - This is 10 times smaller than the correct radius, not accurate. D: 12m - This is much smaller than the correct radius, not accurate.

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.