Nursing Elites

1. Two objects with equal masses collide head-on, both initially moving at the same speed. After the collision, they stick together. What is their final velocity?

• A. Zero
• B. Half their initial velocity
• C. Their initial velocity
• D. Twice their initial velocity

Correct answer: C

Rationale: In an inelastic collision where two objects stick together after colliding, momentum is conserved. Since the two objects have equal masses and equal initial velocities but opposite directions, their momenta cancel out. Therefore, after the collision, the combined mass will move at the same speed as the initial velocity, but in the direction of one of the objects. Choice A ('Zero') is incorrect because momentum is conserved, and the objects must move after the collision. Choice B ('Half their initial velocity') is incorrect as the final velocity is the same as the initial velocity due to momentum conservation. Choice D ('Twice their initial velocity') is incorrect as the final velocity cannot be twice the initial velocity based on the conservation of momentum principle.

2. Identify the spectator ions in the reaction: 2KCl + Pb(NO3)2 → 2KNO3 + PbCl2.

• A. K+ and NO3-
• B. K+ and Cl-
• C. Pb2+ and NO3-
• D. Pb2+ and Cl-

Correct answer: B

Rationale: - In the reaction, potassium ions (K+) and chloride ions (Cl-) are present on both sides of the equation. They are not involved in the formation of the products and remain unchanged. - Lead ions (Pb2+) and nitrate ions (NO3-) are involved in the formation of the products potassium nitrate (KNO3) and lead(II) chloride (PbCl2). - Therefore, the spectator ions in this reaction are K+ and Cl-.

3. What is the term for the distance between the center of a lens or curved mirror and its focal point?

• A. Aperture
• B. Focal length
• C. Refractive index
• D. Lens thickness

Correct answer: B

Rationale: The correct answer is B: Focal length. Focal length is the distance between the center of a lens or curved mirror and its focal point. It determines how strongly the lens converges or diverges light, affecting the image formation. Aperture, choice A, refers to the opening through which light enters the lens, controlling the amount of light passing through. Refractive index, choice C, measures how much light bends when passing through a medium, affecting the speed of light. Lens thickness, choice D, is the physical dimension of the lens, influencing optical properties and compatibility with frames.

4. Which of the following components of the human integumentary system is the deepest?

• A. Stratum basale
• B. Epidermis
• C. Hypodermis
• D. Dermis

Correct answer: C

Rationale: The hypodermis is the deepest layer of the integumentary system, located below the dermis. It serves as a layer of fat that helps insulate the body, store energy, and provide cushioning. The stratum basale is the deepest layer of the epidermis, not the entire integumentary system. The epidermis is the outermost layer of the skin, followed by the dermis, and then the hypodermis. Therefore, the correct answer is the hypodermis (choice C). Choices A, B, and D are incorrect as they do not represent the deepest layer of the integumentary system.

5. Which of the following is a unit of power?

• A. Newton-meter (N·m)
• B. Joule (J)
• C. Watt (W)
• D. Kilogram (kg)

Correct answer: C

Rationale: The correct answer is C: Watt (W). Power is the rate at which work is done or energy is transferred. The unit of power is the watt (W), named after James Watt, the inventor of the steam engine. A Newton-meter (N·m) is a unit of torque, Joule (J) is a unit of energy, and Kilogram (kg) is a unit of mass, not power. Therefore, choices A, B, and D are incorrect as they represent units of torque, energy, and mass, respectively, and not power.

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