Nursing Elites

1. Two objects attract each other with a gravitational force of 12 units. If the distance between them is halved, what is the new force of attraction between the two objects?

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

Correct answer: C

Rationale: The gravitational force between two objects is inversely proportional to the square of the distance between them. When the distance is halved, the new force of attraction will be 12 units x (1/(0.5)^2) = 12 units x 4 = 24 units. Therefore, the correct answer is C. Choice A and B are incorrect as they do not consider the inverse square law of gravitational force. Choice D is incorrect as reducing the distance between the objects does not lead to a squared increase in force.

2. Two objects attract each other with a gravitational force of 12 units. If you double the distance between the objects, what is the new force of attraction between the two?

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

Correct answer: A

Rationale: The gravitational force between two objects is inversely proportional to the square of the distance between them. If the distance is doubled, the force will be reduced to 1/4 of the original force. Therefore, the new force of attraction between the two objects will be 12 units / 4 = 3 units. Choice A is correct because doubling the distance reduces the force to 1/4 of the original value. Choices B, C, and D are incorrect as they do not consider the inverse square relationship between distance and gravitational force.

3. If a 5-kg ball is moving at 5 m/s, what is its momentum?

• A. 10 kg⋅m/s
• B. 16.2 km/h
• C. 24.75 kg⋅m/s
• D. 25 kg⋅m/s

Correct answer: D

Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the mass of the ball is 5 kg and its velocity is 5 m/s. Therefore, the momentum of the ball is 5 kg × 5 m/s = 25 kg⋅m/s. Choice A (10 kg⋅m/s) is incorrect as it does not account for both mass and velocity. Choice B (16.2 km/h) is incorrect as it provides a speed in a different unit without considering mass. Choice C (24.75 kg⋅m/s) is incorrect as it does not correctly calculate the momentum based on the given mass and velocity.

4. Enthalpy (H) is a thermodynamic property defined as the sum of a system's internal energy (U) and the product of its pressure (P) and volume (V). The relationship between these is:

• A. H = U + PV
• B. H = U - PV
• C. H = U / PV
• D. H = PV / U

Correct answer: A

Rationale: Enthalpy (H) is defined as H = U + PV, where U represents internal energy, P is pressure, and V is volume. Enthalpy includes both the internal energy of a system and the energy required to create space for the system against an external pressure. Therefore, the correct relationship between enthalpy, internal energy, pressure, and volume is H = U + PV. Choice B is incorrect as subtracting PV would not account for the work done against pressure. Choice C is incorrect as dividing U by PV doesn't represent the definition of enthalpy. Choice D is incorrect as dividing PV by U is not the correct relationship based on the definition of enthalpy.

5. A key parameter in fluid selection is specific gravity (SG). For a submerged object in a reference fluid (often water), SG = ρ_object / ρ_reference. An object with SG > 1 will:

• A. Experience a net buoyant force acting upwards
• B. Experience a net buoyant force acting downwards
• C. Remain neutrally buoyant
• D. Require knowledge of the object's volume for buoyancy determination

Correct answer: A

Rationale: When the specific gravity (SG) of an object is greater than 1, it indicates that the object is denser than the reference fluid, which is often water. According to Archimedes' principle, an object with SG > 1 will experience a net buoyant force acting upwards when submerged in the fluid. This is because the buoyant force is greater than the weight of the object, causing it to float. Therefore, the correct answer is A: 'Experience a net buoyant force acting upwards.' Objects with SG < 1 would sink as they are less dense than the fluid, while objects with SG = 1 would be neutrally buoyant, neither sinking nor floating.

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