Nursing Elites

1. 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.

2. Which mathematical quantity is scalar?

• A. Distance
• B. Velocity
• C. Acceleration
• D. Displacement

Correct answer: A

Rationale: Distance is a scalar quantity because it has only magnitude and no direction. It is simply the total length of the path travelled by an object. Scalars are quantities that are fully described by their magnitude alone, without any reference to direction. Velocity and acceleration are vector quantities as they have both magnitude and direction. Displacement is also a vector quantity as it is the change in position of an object and includes both magnitude and direction.

3. Marilyn is driving to a wedding. She drives 4 miles south before realizing that she left the gift at home. She makes a U-turn, returns home to pick up the gift, and sets out again driving south. This time, she drives 1 mile out of her way to pick up a friend. From there, they continue 5 miles more to the wedding. Which of these statements is true about Marilyn’s trip?

• A. The displacement of her trip is 6 miles, and the distance traveled is 6 miles.
• B. The displacement of her trip is 14 miles, and the distance traveled is 14 miles.
• C. The displacement of her trip is 8 miles, and the distance traveled is 14 miles.
• D. The displacement of her trip is 6 miles, and the distance traveled is 14 miles.

Correct answer: C

Rationale: Marilyn’s displacement is calculated based on her final position relative to the starting point. She drives 1 mile to pick up her friend, then 5 miles more to the wedding, totaling 6 miles after returning to her home. So, the correct displacement is 8 miles south from her starting point (4 miles to the gift + 4 miles return + 1 mile to the friend + 5 miles to the wedding). The total distance traveled is 14 miles (adding all the distances). Choice A is incorrect because it miscalculates the displacement. Choice B is incorrect as it overestimates both the displacement and distance traveled. Choice D is incorrect as it underestimates the displacement.

4. What does Coulomb’s law relate to?

• A. electrostatic interaction
• B. rigid body motion
• C. heat conduction
• D. universal gravitation

Correct answer: A

Rationale: Coulomb's law is a fundamental principle in physics that deals with the electrostatic interaction between charged particles. It states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. This law is crucial in understanding and predicting the behavior of electrically charged objects. Choices B, C, and D are incorrect because Coulomb's law specifically focuses on electrostatic interactions between charges, not rigid body motion, heat conduction, or universal gravitation.

5. The Prandtl number (Pr) is a dimensionless property relating:

• A. Viscosity and thermal diffusivity
• B. Density and pressure
• C. Surface tension and pressure
• D. Reynolds number and flow regime

Correct answer: A

Rationale: The Prandtl number (Pr) is a dimensionless number used to characterize fluid flow. It is the ratio of momentum diffusivity to thermal diffusivity. In simpler terms, it relates the ability of a fluid to conduct heat to its ability to conduct momentum. Therefore, the correct relationship is between viscosity and thermal diffusivity, making choice A the correct answer. Choices B, C, and D are incorrect because they do not represent the properties that the Prandtl number relates.

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