Nursing Elites

1. Two objects attract each other with a gravitational force of 12 units. If you double the mass of both objects, what is the new force of attraction between them?

• A. 3 units
• B. 6 units
• C. 24 units
• D. 48 units

Correct answer: C

Rationale: The gravitational force between two objects is directly proportional to the product of their masses. When you double the masses of both objects, the force of attraction between them increases by a factor of 2 x 2 = 4. Therefore, the new force of attraction between the two objects will be 12 units x 4 = 24 units. Choices A, B, and D are incorrect because doubling the mass results in a quadruple increase in force, not a linear one.

2. A system undergoes an isobaric process (constant pressure). In this process, the work done (W) by the system is:

• A. Zero, if the volume change (ΔV) is zero.
• B. Positive and equal to the pressure multiplied by the volume change (W = PΔV).
• C. Negative and equal to the pressure multiplied by the volume change.
• D. Independent of the pressure or volume change.

Correct answer: B

Rationale: In an isobaric process (constant pressure), the work done is given by the formula W = PΔV, where P is the pressure and ΔV is the change in volume. If the volume does not change, the work done is zero, not negative. Choice A is incorrect as it states the work done is zero when the volume change is zero, which is the correct condition for zero work. Choice C is incorrect as it incorrectly suggests that the work done is negative in an isobaric process. Choice D is incorrect as the work done in an isobaric process is indeed dependent on the volume change and pressure.

3. Fluids can be categorized based on their shear stress-strain rate relationship. An ideal fluid exhibits:

• A. Zero shear stress at any strain rate
• B. Linear relationship between shear stress and strain rate (Newtonian)
• C. Non-linear relationship between shear stress and strain rate (Non-Newtonian)
• D. High dependence of viscosity on temperature

Correct answer: A

Rationale: An ideal fluid, often referred to as an inviscid fluid, is a theoretical concept used in fluid mechanics to simplify calculations. It is characterized by having zero shear stress at any strain rate. In reality, such fluids do not exist, but they serve as a useful starting point for understanding fluid behavior in idealized situations. Choice B is incorrect because a linear relationship between shear stress and strain rate defines a Newtonian fluid, not an ideal fluid. Choice C is incorrect because a non-linear relationship between shear stress and strain rate characterizes Non-Newtonian fluids, not ideal fluids. Choice D is incorrect because the high dependence of viscosity on temperature is a characteristic seen in real fluids and does not define an ideal fluid.

4. Jack stands in front of a plane mirror. If he is 5 feet away from the mirror, how far away from Jack is his image?

• A. 2.5 feet
• B. 3 feet
• C. 4.5 feet
• D. 5 feet

Correct answer: D

Rationale: When Jack stands in front of a plane mirror, his image appears the same distance behind the mirror as Jack is in front of it. Therefore, if Jack is 5 feet away from the mirror, his image will also appear 5 feet behind the mirror. The total distance from Jack to his image is the sum of these distances, which equals 10 feet. Choices A, B, and C are incorrect because the image distance is not half of the total distance but the same as the object's distance from the mirror.

5. What is the primary factor responsible for generating lift on an airplane wing?

• A. Propulsion force generated by the engines
• B. Buoyant forces acting on the entire aircraft
• C. Drag reduction achieved through streamlining
• D. Application of Bernoulli's principle to the airfoil's shape

Correct answer: D

Rationale: The primary factor responsible for generating lift on an airplane wing is the application of Bernoulli's principle. This principle states that the air moving over the curved top surface of the wing has to travel faster, leading to reduced pressure above the wing and creating lift. Engines provide thrust for propulsion, not lift. Buoyant forces are more relevant to lighter-than-air aircraft like balloons or airships, not airplanes. While drag reduction through streamlining is important for efficiency, it is not the primary factor in lift generation. Therefore, the correct answer is D.

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