Nursing Elites

1. What is the momentum of a car with a mass of 1500 kg moving at a speed of 20 m/s?

• A. 30,000 kg m/s
• B. 1500 kg m/s
• C. 20 kg m/s
• D. Momentum cannot be determined without knowing the direction of motion.

Correct answer: A

Rationale: The momentum of an object is calculated by multiplying its mass by its velocity. In this case, the momentum of the car can be determined using the formula momentum = mass x velocity. Substituting the given values, momentum = 1500 kg x 20 m/s = 30,000 kg m/s. Therefore, the correct answer is A, 30,000 kg m/s. Choice B (1500 kg m/s) is incorrect because that value represents the mass of the car, not its momentum. Choice C (20 kg m/s) is incorrect as it only represents the speed of the car, not its momentum. Choice D (Momentum cannot be determined without knowing the direction of motion) is incorrect because momentum is a vector quantity and can be determined using magnitude and direction, but in this case, only the magnitude is required.

2. 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.

3. Calcitonin, a hormone that helps regulate calcium levels, is produced by the:

• A. Thyroid gland
• B. Parathyroid gland
• C. Thymus gland
• D. Adrenal gland

Correct answer: A

Rationale: Calcitonin is a hormone produced by the thyroid gland. It helps regulate calcium levels in the body by inhibiting the breakdown of bone and promoting calcium excretion by the kidneys. The parathyroid gland produces parathyroid hormone (PTH), which works in opposition to calcitonin to regulate calcium levels. The thymus gland is involved in the development of the immune system, and the adrenal gland produces hormones such as cortisol and adrenaline. Therefore, the correct answer is the thyroid gland as it specifically secretes calcitonin for calcium regulation.

4. Which of the following is NOT a major division of the nervous system?

• A. Peripheral nervous system
• B. Central nervous system
• C. Somatic nervous system
• D. Autonomic nervous system

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The major divisions of the nervous system are the central nervous system, which includes the brain and spinal cord, and the peripheral nervous system, which includes all the nerves outside of the central nervous system. The somatic nervous system, which controls voluntary movements and reflexes, is a part of the peripheral nervous system. The autonomic nervous system is another subdivision of the peripheral nervous system that regulates involuntary functions like heart rate and digestion. Therefore, the somatic nervous system is not a major division of the nervous system, making it the correct answer.

5. What type of epithelium lines the inner surface of blood vessels?

• A. Simple squamous epithelium
• B. Simple columnar epithelium
• C. Stratified squamous epithelium
• D. Stratified columnar epithelium

Correct answer: A

Rationale: The correct answer is simple squamous epithelium (Choice A). The inner surface of blood vessels is lined by a single layer of flattened cells, known as simple squamous epithelium. This epithelium type is thin and allows for efficient diffusion and filtration, which is essential for the exchange of gases and nutrients across blood vessel walls. Simple columnar epithelium (Choice B) is typically found in the lining of the gastrointestinal tract and is responsible for absorption and secretion. Stratified squamous epithelium (Choice C) is commonly found in the skin, providing protection against mechanical stress. Stratified columnar epithelium (Choice D) is not a characteristic epithelium type found in the lining of blood vessels, as it is more commonly present in specific regions of the body like parts of the male urethra and the conjunctiva of the eye.

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