HESI A2 Physics

Correct Answer: C

Rationale: The correct answer is C (24 units). When you double the mass of both objects, the gravitational force between them increases by a factor of 4 (2 times 2). Therefore, the new force of attraction would be 12 units x 4 = 24 units. Choice A (3 units) and B (6 units) are incorrect because they do not account for the increase in mass. Choice D (48 units) is incorrect as it overestimates the effect of doubling the mass on the gravitational force.

Correct Answer: D

Rationale: The correct answer is D: Strongly repulsive. When two identical positively charged spheres are brought close together, they will experience a strong repulsive force due to like charges repelling each other based on Coulomb's Law. The force between them is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. The repulsive force will increase as the spheres get closer, leading to a strong repulsion. Choices A and C are incorrect because like charges do not attract each other. Choice B is incorrect as the spheres will experience a repulsive force, not a zero force.

Correct Answer: C

Rationale: Step 1: Energy consumption is typically measured in kilowatt-hours. Step 2: Power (in watts) is the rate at which energy is used. Step 3: Energy = Power x Time, as energy consumed is the product of power and time. Step 4: Therefore, the correct expression is Energy = Power x Time (Choice C). Summary: - Choice A is incorrect because power is the rate of energy consumption, not the total energy used. - Choice B is incorrect as it incorrectly combines time and energy without considering the power. - Choice D is incorrect as it rearranges the formula incorrectly, dividing energy by power instead of multiplying.

Correct Answer: D

Rationale: The correct answer is D: Cannot be created or destroyed. According to the law of conservation of energy, energy can neither be created nor destroyed, but only transformed from one form to another. This principle is a fundamental law of physics known as the first law of thermodynamics. Any process involving energy transfer must adhere to this law. Choices A, B, and C are incorrect because they contradict this fundamental principle. Energy cannot be created out of nothing or disappear completely; it can only change forms.

Correct Answer: C

Rationale: The correct answer is C because longitudinal waves have vibrations that move in the same direction as the wave propagation. In a longitudinal wave, the particles oscillate parallel to the direction of the wave's movement, creating compressions and rarefactions. Option A is incorrect as vibrations in longitudinal waves are not perpendicular. Option B is incorrect because vibrations do not move in the opposite direction of the wave. Option D is incorrect as waves and troughs are not relevant to the direction of vibrations in longitudinal waves.