Nursing Elites

1. Which vehicle has the greatest momentum?

• A. A 9,000-kg railroad car traveling at 3 m/s
• B. A 2,000-kg automobile traveling at 24 m/s
• C. A 1,500-kg MINI Coupe traveling at 29 m/s
• D. A 500-kg glider traveling at 89 m/s

Correct answer: D

Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. The momentum formula is p = m × v, where p is momentum, m is mass, and v is velocity. Comparing the momentum of each vehicle: A: 9,000 kg × 3 m/s = 27,000 kg·m/s B: 2,000 kg × 24 m/s = 48,000 kg·m/s C: 1,500 kg × 29 m/s = 43,500 kg·m/s D: 500 kg × 89 m/s = 44,500 kg·m/s. Therefore, the glider (500-kg) traveling at 89 m/s has the greatest momentum of 44,500 kg·m/s, making it the correct choice. Options A, B, and C have lower momentum values compared to option D, proving that the 500-kg glider traveling at 89 m/s has the highest momentum among the given vehicles.

2. The drag force (F_d) experienced by an object moving through a fluid depends on:

• A. Object's shape and size only
• B. Fluid properties and object velocity
• C. Depth of submersion only
• D. Buoyant force acting on the object

Correct answer: B

Rationale: The drag force experienced by an object moving through a fluid depends on multiple factors, including the object's shape, size, velocity, and the fluid's properties such as viscosity and density. Choices A, C, and D are incorrect because drag force is not solely determined by the object's shape and size, depth of submersion, or buoyant force acting on the object. The primary factors affecting drag force are the fluid properties and the object's velocity. Therefore, the correct answer is B.

3. An object with a charge of 4 μC is placed 50 cm from another object with a charge twice as great. What is the magnitude of the resulting repulsive force?

• A. 0.1152 N
• B. 1.152 N
• C. 10^−3 N
• D. 2.5 × 10^−3 N

Correct answer: D

Rationale: The force between two charges is calculated using Coulomb's Law, which states that the force is proportional to the product of the two charges and inversely proportional to the square of the distance between them. Given that one charge is twice as great as the other and the distance between them is 50 cm, we can calculate the repulsive force. The magnitude of the resulting repulsive force is 2.5 × 10^−3 N. Choice A is incorrect as it does not match the calculated value. Choice B is incorrect as it is significantly higher than the correct answer. Choice C is incorrect as it represents 10^−3 N, which is lower than the calculated value.

4. In terms of electrical conductivity, semiconductors fall between

• A. Conductors and insulators
• B. Conductors and superconductors
• C. Insulators and dielectrics
• D. Superconductors and insulators

Correct answer: A

Rationale: Semiconductors have electrical conductivities that lie between those of conductors (high conductivity) and insulators (low conductivity). This positioning makes choice A, 'Conductors and insulators,' the correct answer. Choice B, 'Conductors and superconductors,' is incorrect because superconductors have perfect conductivity, not intermediate like semiconductors. Choice C, 'Insulators and dielectrics,' is incorrect because dielectrics are a type of insulator, so it doesn't show the progression from high to low conductivity. Choice D, 'Superconductors and insulators,' is incorrect because superconductors have the highest conductivity, opposite to the role of semiconductors.

5. Two 5-ohm resistors are placed in series and wired into a 100-V power supply. What current flows through this circuit?

• A. 2 A
• B. 10 A
• C. 20 A
• D. 50 A

Correct answer: B

Rationale: In a series circuit, the total resistance is the sum of the individual resistances. Therefore, the total resistance in this circuit is 5 ohms + 5 ohms = 10 ohms. Using Ohm's Law (V = I × R), we can find the current (I) by dividing the voltage (V) by the total resistance (R). I = V / R = 100 V / 10 ohms = 10 A. Choice A (2 A) is incorrect because it does not account for the total resistance of the circuit. Choice C (20 A) and Choice D (50 A) are also incorrect as they provide values that are not consistent with the calculations based on the given values in the question.

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