HESI Exams Quizlet Physics

Correct Answer: C

Rationale: Step-by-step rationale: 1. Archimedes' principle states that the buoyant force on an object is equal to the weight of the fluid displaced. 2. Submarines adjust their buoyancy by changing the amount of water they displace, allowing them to submerge or resurface. 3. This control of buoyancy is crucial for submarines to navigate underwater efficiently while conserving energy. 4. Choice A is incorrect as density differences affect buoyancy, not causing objects to sink regardless. 5. Choice B is incorrect as airplane lift is generated by the Bernoulli principle and wing design, not Archimedes' principle. 6. Choice D is incorrect as helium balloons float due to buoyancy force exceeding their weight, not overcoming gravity.

Correct Answer: A

Rationale: The correct answer is A: 10 m/s. Velocity is calculated by dividing the distance traveled by the time taken. In this case, velocity = 100m / 10s = 10 m/s. Choice B, 90 m/s, is incorrect because it is not the accurate calculation. Choice C, 110 m/s, and choice D, 1,000 m/s, are both incorrect as they do not align with the correct formula for calculating velocity. The key is to remember that velocity is a vector quantity that includes both speed and direction, and in this case, we are only concerned with the speed of the object, making choice A the correct answer.

Correct Answer: C

Rationale: Potential energy increases as particles approach each other because the distance between them decreases, leading to an increase in repulsive forces due to the close proximity of the particles. This causes the potential energy to rise as the particles try to move away from each other to reduce the repulsive forces. Attractive forces do not increase in this scenario, and in fact, they may decrease due to the particles being closer together. Repulsive forces increase as the particles get closer, not decrease. Therefore, the correct answer is C.

Correct Answer: A

Rationale: When you double the distance between two objects, the gravitational force between them decreases by a factor of 4 (inverse square law). So, if the original force was 12 units, when you double the distance, the new force will be 12/4 = 3 units. Therefore, the correct answer is A: 3 units. Summary: - Choice A (3 units) is correct as the force decreases by a factor of 4 when the distance is doubled. - Choices B (6 units), C (24 units), and D (48 units) are incorrect as they do not consider the inverse square law of gravitational force.

Correct Answer: A

Rationale: Conduction is the transfer of heat through a material without any movement of the material itself. In contrast, convection involves the movement of fluids to transfer heat, radiation transfers heat through electromagnetic waves, and isothermalization is not a recognized mode of heat transfer. Therefore, the correct answer is A because it does not involve the movement of material or fluid to transfer heat like convection does. Convection, radiation, and isothermalization are all modes of heat transfer, making them incorrect choices.