HESI A2 Physics Quizlet

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: C

Rationale: Step-by-step rationale for why choice C is correct: 1. The first law of thermodynamics is based on the principle of energy conservation. 2. Choice C accurately reflects this principle by stating that energy cannot be created or destroyed, only transferred or transformed. 3. This is in line with the law of conservation of energy, which is a fundamental concept in physics. 4. Choices A, B, and D are incorrect because they do not accurately represent the first law of thermodynamics. 5. Choice A violates the principle of conservation of energy, choice B refers to the second law of thermodynamics, and choice D is not directly related to the first law.

Correct Answer: C

Rationale: To calculate work, we use the formula Work = Force × Distance. In this scenario, Amanda exerts a force of 100 N to push the lawnmower a total distance of 20 rows × 30 meters/row = 600 meters. Therefore, the work done is 100 N × 600 m = 60,000 N⋅m. This is why choice C, 60,000 N⋅m, is correct. Choices A and B are incorrect as they do not accurately calculate the work done. Choice D is also incorrect as we can determine the work done using the provided information.

Correct Answer: D

Rationale: Surface tension is the result of cohesive forces between liquid molecules at the surface, creating a net inward force. When a small object floats on the liquid surface, the surface tension exerts a restoring force towards equilibrium, keeping the object stable. This force pulls the object back towards the liquid surface if it is displaced. This is why choice D, "Restoring force towards equilibrium," is the correct answer. Choices A, B, and C are incorrect. Buoyant force (A) acts on objects immersed in a fluid, not on objects floating on the surface. Pressure difference (B) would not cause sinking of a floating object. Drag force (C) is a resistance force that opposes motion, not related to surface tension in this context.

Correct Answer: D

Rationale: To find the resistance, we use Ohm's Law: R = V/I. Given V = 120V and I = 25A, we have R = 120V / 25A = 4.8 ohms. Therefore, choice D is correct. Choice A (96 ohms) is incorrect as it does not match the calculated value. Choice B (104 ohms) and choice C (150 ohms) are also incorrect as they do not match the correct resistance value of 4.8 ohms.