Nursing Elites

1. Which of the following substances has the highest density?

• A. Mist
• B. Water
• C. Steam
• D. Ice

Correct answer: B

Rationale: Water has the highest density among the options provided. Density is a measure of mass per unit volume. In this case, water in its liquid form is denser than mist, steam, and ice. Ice has a lower density than water because its crystalline structure causes it to be less dense. Mist and steam are forms of water vapor, which are much less dense than liquid water. Therefore, the correct answer is water (choice B).

2. Given the four wires described here, which would you expect to have the greatest resistance?

• A. 1 km of American wire gauge 1; diameter 7.35 mm
• B. 1 km of American wire gauge 2; diameter 6.54 mm
• C. 1 km of American wire gauge 3; diameter 5.83 mm
• D. 1 km of American wire gauge 4; diameter 5.19 mm

Correct answer: D

Rationale: The wire with the greatest resistance is the one with the smallest diameter, as resistance is inversely proportional to cross-sectional area. Gauge 4 with a 5.19 mm diameter has the smallest diameter and, therefore, the greatest resistance. Choice A, B, and C have larger diameters compared to choice D, so they would have lower resistance values.

3. Capillarity describes the tendency of fluids to rise or fall in narrow tubes. This phenomenon arises from the interplay of:

• A. Buoyancy and pressure differentials
• B. Density variations and compressibility of the fluid
• C. Viscous dissipation and inertial effects
• D. Surface tension at the liquid-gas interface and intermolecular forces

Correct answer: D

Rationale: Capillarity occurs due to surface tension and intermolecular forces between the liquid and the walls of the narrow tube. These forces cause the liquid to rise or fall depending on the cohesion and adhesion properties. Surface tension at the liquid-gas interface and intermolecular forces are responsible for capillary action, making choice D the correct answer. Choices A, B, and C are incorrect as they do not directly relate to the specific forces involved in capillarity.

4. Why does potential energy increase as particles approach each other?

• A. Attractive forces increase.
• B. Attractive forces decrease.
• C. Repulsive forces increase.
• D. Repulsive forces decrease.

Correct answer: C

Rationale: The correct answer is C: Repulsive forces increase. As particles approach each other, the distance between them decreases, causing the repulsive forces between the particles to increase. This increase in repulsive forces leads to an increase in potential energy as the particles resist being pushed closer together. Choices A and B are incorrect because attractive forces do not increase or decrease in this scenario. Choice D is incorrect because repulsive forces actually increase as particles get closer, leading to a rise in potential energy.

5. A box is moved by a 15 N force over a distance of 3 m. What is the amount of work that has been done?

• A. 5 W
• B. 5 N⋅m
• C. 45 W
• D. 45 N⋅m

Correct answer: D

Rationale: Work done is calculated using the formula: Work = Force x Distance. In this case, the force applied is 15 N and the distance covered is 3 m. Thus, work done = 15 N x 3 m = 45 N⋅m. Therefore, the correct answer is 45 N⋅m. Choice A (5 W) is incorrect because work is measured in joules (J) or newton-meters (N⋅m), not in watts (W). Choice B (5 N⋅m) is incorrect as it miscalculates the work by not multiplying the force by the distance. Choice C (45 W) is incorrect because work is not measured in watts (W) but in newton-meters (N⋅m).

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