Nursing Elites

1. Which of the following materials has the lowest density?

• A. Water
• B. Cork
• C. Aluminum
• D. Steel

Correct answer: B

Rationale: Cork has the lowest density among the given options. Cork is a lightweight material derived from the bark of cork oak trees and is known for its low density, making it float on water. Water, aluminum, and steel have higher densities compared to cork. Water is denser than cork because it has a consistent density of 1 g/cm³. Aluminum and steel are metals with much higher densities due to their atomic structures, making them denser than cork.

2. According to the zeroth law of thermodynamics, two systems are in thermal equilibrium if:

• A. They have the same pressure.
• B. They have the same volume.
• C. They have the same temperature.
• D. They are made of the same material.

Correct answer: C

Rationale: The correct answer is C: "They have the same temperature." The zeroth law of thermodynamics states that if two systems are each in thermal equilibrium with a third system, they are also in thermal equilibrium with each other. This implies that they have the same temperature. Choice A is incorrect because pressure is not the determining factor for thermal equilibrium. Choice B is incorrect because volume alone does not dictate thermal equilibrium. Choice D is incorrect as the materials the systems are made of do not determine thermal equilibrium according to the zeroth law of thermodynamics.

3. Longitudinal waves have vibrations that move ___________.

• A. at right angles to the direction of the vibrations
• B. in the direction opposite to that of the wave
• C. in the same direction as the wave
• D. in waves and troughs

Correct answer: C

Rationale: In longitudinal waves, the vibrations of particles occur in the same direction as the wave propagates. This means the particles move back and forth in the direction of the wave, creating compressions and rarefactions along the wave. Therefore, the correct choice is C, in the same direction as the wave. Choice A is incorrect because transverse waves, not longitudinal waves, have vibrations at right angles to the direction of wave propagation. Choice B is incorrect as it describes the motion in transverse waves. Choice D is incorrect as it is an inaccurate representation of how longitudinal waves propagate.

4. An object moves 100 m in 10 s. What is the velocity of the object over this time?

• A. 10 m/s
• B. 90 m/s
• C. 110 m/s
• D. 1,000 m/s

Correct answer: A

Rationale: Velocity is calculated as the displacement divided by the time taken to cover that displacement. In this case, the object moves 100 meters in 10 seconds. Therefore, the velocity is 100 m / 10 s = 10 m/s. Choice B, 90 m/s, is incorrect as it doesn't match the calculated velocity. Choice C, 110 m/s, is incorrect as it is higher than the calculated velocity. Choice D, 1,000 m/s, is incorrect as it is significantly higher than the calculated velocity.

5. A 1,000-kg car drives at 10 m/s around a circle with a radius of 50 m. What is the centripetal acceleration of the car?

• A. 2 m/s²
• B. 4 m/s²
• C. 5 m/s²
• D. 10 m/s²

Correct answer: A

Rationale: Centripetal acceleration is calculated using the formula a = v² / r, where v = 10 m/s and r = 50 m. Substituting these values: a = (10 m/s)² / 50 m = 100 / 50 = 2 m/s². Therefore, the correct answer is 2 m/s². Choice B, 4 m/s², is incorrect because it is not the result of the correct calculation. Choice C, 5 m/s², is incorrect as it does not match the calculated centripetal acceleration. Choice D, 10 m/s², is incorrect as it does not reflect the correct calculation based on the given values.

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