Nursing Elites

1. What force was applied to the object that was moved if 100 Nâ‹…m of work is done over 20 m?

• A. 5 N
• B. 80 N
• C. 120 N
• D. 2,000 N

Correct answer: A

Rationale: Work is calculated using the formula Work = Force x Distance. Given that 100 Nâ‹…m of work is done over 20 m, we can rearrange the formula to solve for Force. Force = Work / Distance. Plugging in the values, we get Force = 100 Nâ‹…m / 20 m = 5 N. Therefore, the force applied to the object that was moved is 5 N. Choice B (80 N) is incorrect because it doesn't match the calculated force of 5 N. Choice C (120 N) is incorrect as it is higher than the calculated force. Choice D (2,000 N) is incorrect as it is significantly higher than the correct force of 5 N.

2. Surface tension, γ, is a property of fluids arising from:

• A. Intermolecular forces between fluid molecules
• B. Gravitational attraction
• C. Viscous dissipation
• D. Pressure differentials within the fluid

Correct answer: A

Rationale: Surface tension, represented by symbol γ, is caused by the cohesive forces between molecules in a liquid. These intermolecular forces, such as Van der Waals forces, hydrogen bonding, and dipole-dipole interactions, create a 'skin' at the surface of the liquid, giving rise to the property of surface tension. Gravitational attraction, viscous dissipation, and pressure differentials within the fluid do not directly contribute to surface tension. Therefore, the correct answer is A.

3. In a U-tube manometer, a fluid is used to measure pressure differences. When one side is connected to a pressurized system, the fluid level on that side will:

• A. Remain the same
• B. Decrease
• C. Increase
• D. Depend on the type of fluid used

Correct answer: B

Rationale: In a U-tube manometer, the side connected to a pressurized system will experience a decrease in fluid level due to the pressure exerted by the system. This pressure forces the fluid down, causing the fluid level to decrease. Therefore, choice B is correct. Choices A and C are incorrect because the fluid level will not remain the same or increase when connected to a pressurized system. Choice D is incorrect as the type of fluid used does not determine the direction of the fluid movement in response to pressure.

4. 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.

5. A 0-kg block on a table is given a push so that it slides along the table. If the block is accelerated at 6 m/s2, what was the force applied to the block?

• A. 0 N
• B. 3 N
• C. 6 N
• D. The answer cannot be determined from the information given.

Correct answer: A

Rationale: According to Newton's second law of motion, F=ma. Since the block has a mass of 0 kg, the force applied must be 0 N, as no force is needed to move an object with zero mass.

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