Nursing Elites

1. An object with a charge of 4 μC is placed 1 meter from another object with a charge of 2 μC. What is the magnitude of the resulting force between the objects?

• A. 0.04 N
• B. 0.072 N
• C. 80 N
• D. 8 × 10−6 N

Correct answer: A

Rationale: To find the magnitude of the resulting force between two charges, we can use Coulomb's law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. The formula for Coulomb's law is: F = k × (|q1 × q2| / r²), where F is the force, k is the Coulomb constant, q1 and q2 are the charges, and r is the distance between the charges. Substituting the given values into the formula: F = (9 × 10⁹ N·m²/C²) × ((4 × 10⁻⁶ C) × (2 × 10⁻⁶ C) / (1 m)²) = 0.04 N. Therefore, the magnitude of the resulting force between the objects is 0.04 N.

2. Energy manifests in various forms. Which of the following is NOT considered a fundamental energy type?

• A. Thermal energy
• B. Momentum
• C. Sound energy
• D. Chemical energy

Correct answer: B

Rationale: The correct answer is B. Momentum is not considered a form of energy; it is a property of moving objects. Thermal, sound, and chemical energy are all forms of energy. Thermal energy is the energy associated with the movement of particles within an object. Sound energy is produced by vibrations and travels through materials as waves. Chemical energy is stored within the bonds of chemical compounds. While momentum is a crucial concept in physics, it is not a fundamental form of energy.

3. Which of these objects has the greatest momentum?

• A. A 1,250-kg car moving at 5 m/s
• B. An 80-kg person running at 4 m/s
• C. A 10-kg piece of meteorite moving at 600 m/s
• D. A o.5-kg rock moving at 40 m/s

Correct answer: A

Rationale: Momentum is the product of mass and velocity. The car has the highest momentum because it has the largest mass and a significant velocity.

4. 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.

5. In open-channel flow, a critical property is the free surface, which refers to the:

• A. Interface between the liquid and the container walls
• B. Interface between the liquid and a surrounding gas
• C. Bottom of the channel
• D. Region of highest velocity within the liquid

Correct answer: B

Rationale: The free surface in open-channel flow refers to the interface between the liquid and the surrounding gas, typically the atmosphere. This interface is critical as it determines the boundary between the liquid flow and the open environment. Option A is incorrect as it refers to the liquid-container wall interface, not the free surface. Option C is incorrect because it represents the bottom of the channel, not the free surface. Option D is incorrect as it describes the region of highest velocity within the liquid, not the free surface. Therefore, the correct choice is B.

Similar Questions