Nursing Elites

1. What type of force enables a car to take a sharp turn while moving in a circular path?

• A. Centripetal force
• B. Tension force
• C. Frictional force
• D. Gravitational force

Correct answer: A

Rationale: Centripetal force is the force that allows an object to move in a circular path. When a car takes a sharp turn, centripetal force acts towards the center of the circle, enabling the car to stay in the curved path. Tension force is transmitted through a string, rope, cable, or wire when pulled tight, and it is not directly related to a car's turning motion. Frictional force opposes motion and is not the primary force responsible for a car's ability to take a sharp turn. Gravitational force is the attraction between masses and does not directly influence a car's ability to maneuver in a curved path.

2. What is the action of the triceps reflex?

• A. Forces contraction of the triceps and extension of the arm.
• B. Forces contraction of the biceps, relaxation of the biceps, and arm extension.
• C. Causes the triceps to contract, causing the forearm to supinate and flex.
• D. Causes the triceps to relax and the upper arm to pronate and extend.

Correct answer: A

Rationale: The triceps reflex causes the triceps muscle to contract, leading to the extension of the arm. This reflex is a protective response to sudden stretching of the triceps muscle, as seen when a physician taps the triceps tendon during a physical examination. Choice A is the correct answer as it accurately reflects the action of the triceps reflex. Choices B, C, and D are incorrect because they describe actions that are not associated with the triceps reflex. Biceps contraction, forearm supination, flexion, triceps relaxation, and pronation are not part of the triceps reflex arc.

3. What effect does doubling the net force applied to an object have on its acceleration, assuming mass remains constant?

• A. Acceleration doubles
• B. Acceleration is halved
• C. Acceleration remains the same
• D. Acceleration quadruples

Correct answer: A

Rationale: According to Newton's second law of motion, acceleration is directly proportional to the net force applied to an object when mass is constant. Therefore, if the net force is doubled, the acceleration of the object will also double. This relationship is expressed by the formula F=ma, where F is the net force, m is the mass, and a is the acceleration. When mass is constant, doubling the force applied will result in a proportional doubling of acceleration. Choices B, C, and D are incorrect because doubling the net force does not halve, maintain, or quadruple the acceleration; it directly and proportionally increases the acceleration.

4. Which hormone is responsible for regulating sleep-wake cycles and is influenced by light exposure?

• A. Melatonin
• B. Cortisol
• C. Estrogen
• D. Glucagon

Correct answer: A

Rationale: The correct answer is A: Melatonin. Melatonin is the hormone responsible for regulating sleep-wake cycles, also known as the circadian rhythm. Its production is influenced by light exposure, with levels increasing in the evening in response to darkness, signaling the body that it is time to sleep. Choice B, cortisol, is a stress hormone and does not directly regulate sleep-wake cycles. Choice C, estrogen, is a sex hormone and is not primarily involved in regulating sleep. Choice D, glucagon, is a hormone that increases blood glucose levels and is not related to sleep-wake cycles.

5. What property of a substance refers to its ability to undergo a chemical change and form new substances with different properties?

• A. Density
• B. Mass
• C. Reactivity
• D. Volume

Correct answer: C

Rationale: Reactivity is the property of a substance that describes its ability to undergo a chemical change and form new substances with different properties. Density (A), mass (B), and volume (D) are physical properties of a substance and do not directly relate to its ability to undergo chemical changes. Density is mass per unit volume, mass is the amount of matter in a substance, and volume is the space occupied by a substance.

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