Nursing Elites

1. What is the main factor affecting the acceleration of a ball rolling down an inclined plane?

• A. The material of the ball
• B. The angle of the incline
• C. The air resistance
• D. The ball's initial velocity

Correct answer: B

Rationale: The main factor affecting the acceleration of a ball rolling down an inclined plane is the angle of the incline. The steeper the incline, the greater the component of the gravitational force acting parallel to the incline, leading to a higher acceleration of the ball. While the material of the ball, air resistance, and the ball's initial velocity may have some influence on the motion, the angle of the incline is the primary factor determining acceleration in this scenario. The material of the ball does not significantly affect its acceleration on the incline unless it impacts the friction with the surface. Air resistance plays a minor role in the acceleration of the ball compared to the gravitational force. The ball's initial velocity affects the speed at the start but does not influence the acceleration down the incline.

2. What happens to the density of a substance if its mass increases while its volume remains constant?

• A. Density increases
• B. Density decreases
• C. Density remains constant
• D. Density becomes zero

Correct answer: A

Rationale: When the mass of a substance increases while its volume remains constant, the density, which is calculated by dividing mass by volume, will increase. This is because with a higher mass and the volume staying the same, the ratio of mass to volume (density) will be greater, resulting in an overall increase in density. Choice B, 'Density decreases,' is incorrect because an increase in mass with constant volume leads to a higher density. Choice C, 'Density remains constant,' is incorrect as an increase in mass will cause the density to increase. Choice D, 'Density becomes zero,' is incorrect because even with an increase in mass, as long as volume remains constant, density will not reach zero; it will increase instead.

3. The function of synergists can best be described as which of the following? I. They assist primary movers in completing the specific movement II. They stabilize the point of origin and provide extra pull near the insertion III. They help prevent unwanted movement at a joint

• A. I, II
• B. I, III
• C. II, III
• D. All of the above

Correct answer: A

Rationale: Synergists are muscles that assist the primary movers (agonists) in completing specific movements (I). Additionally, they stabilize the point of origin and provide extra pull near the insertion, aiding in movement efficiency (II). While synergists may contribute to stability, their primary role is to assist in movement rather than prevent unwanted movement at a joint; hence, options I and II offer the most accurate descriptions of their function. Choice B is incorrect because synergists do not primarily help prevent unwanted movement at a joint (III). Choice C is incorrect as it combines stabilization of the point of origin and preventing unwanted movement, which is not the primary function of synergists.

4. Which feedback loops are less common and sometimes harmful because they enhance stimuli rather than inhibit them?

• A. Negative feedback loop
• B. Positive feedback loop
• C. Inhibitory feedback loop
• D. Stimulating feedback loop

Correct answer: B

Rationale: Correct. Positive feedback loops enhance or amplify changes, which can sometimes be harmful as they drive processes further from equilibrium. In contrast, negative feedback loops work to counteract deviations from a set point, promoting stability. Choice A, 'Negative feedback loop,' is incorrect because negative feedback loops inhibit or reduce changes, promoting stability. Choice C, 'Inhibitory feedback loop,' is incorrect as it is synonymous with negative feedback loops. Choice D, 'Stimulating feedback loop,' is incorrect as it inaccurately describes the nature of positive feedback loops.

5. Which nervous system controls the involuntary 'fight-or-flight' response?

• A. Sympathetic nervous system
• B. Parasympathetic nervous system
• C. Enteric nervous system
• D. Sensory nervous system

Correct answer: A

Rationale: The correct answer is the sympathetic nervous system. The sympathetic nervous system is responsible for activating the body's response to stress or danger, leading to the 'fight-or-flight' response. It prepares the body for action by increasing heart rate, dilating pupils, and redirecting blood flow to muscles. Choice B, the parasympathetic nervous system, is responsible for the body's 'rest-and-digest' activities, which are opposite to the 'fight-or-flight' response. Choice C, the enteric nervous system, primarily regulates the gastrointestinal system and is not directly involved in the 'fight-or-flight' response. Choice D, the sensory nervous system, transmits sensory information from the body to the central nervous system and is not responsible for the physiological changes associated with the 'fight-or-flight' response.

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