Nursing Elites

1. Which of the following scenarios represents an example of static friction?

• A. Sliding a heavy box across the floor
• B. A car moving around a curve
• C. Pushing a stationary object
• D. Braking a car to stop

Correct answer: C

Rationale: The correct answer is C. Static friction occurs when two surfaces are in contact but not moving relative to each other. Pushing a stationary object involves static friction as you apply a force to overcome the friction keeping the object stationary. Choices A, B, and D involve kinetic friction, which occurs when two surfaces are moving relative to each other. Option A involves moving the box across the floor, which is an example of kinetic friction. Option B involves the movement of a car around a curve, which also relates to kinetic friction due to the relative movement between the tires and the road. Option D describes braking a car to stop, where the moving car's wheels interact with the road, creating kinetic friction to slow down and stop the car.

2. A light ray travels from air (refractive index 1.00) into water (refractive index 1.33). What happens to its speed and direction?

• A. Speed increases, direction bends towards the normal.
• B. Speed increases, direction bends away from the normal.
• C. Speed decreases, direction bends towards the normal.
• D. Speed and direction remain unchanged.

Correct answer: C

Rationale: When a light ray travels from air (lower refractive index) to water (higher refractive index), its speed decreases due to the change in the medium. This is because light travels slower in denser mediums. As the light ray enters the denser medium, water in this case, it bends towards the normal (the line perpendicular to the surface of the water). This phenomenon is known as refraction. Choice A is incorrect as the speed of light decreases when entering a denser medium. Choice B is incorrect as the direction bends towards the normal, not away from it. Choice D is incorrect as the speed and direction of the light ray do change when moving from air to water.

3. An atom has 5 protons, 5 neutrons, and 6 electrons. What is the electric charge of this atom?

• A. Neutral
• B. Positive
• C. Negative
• D. Undetermined

Correct answer: C

Rationale: The correct answer is 'Negative.' An atom becomes negatively charged when it has more electrons than protons. In this case, the atom has 6 electrons and 5 protons, resulting in a net negative charge. Choice A 'Neutral' is incorrect because the atom is not balanced in terms of protons and electrons. Choice B 'Positive' is incorrect because having more electrons than protons results in a negative charge. Choice D 'Undetermined' is incorrect, as the charge can be determined based on the relative number of protons and electrons.

4. What phenomenon explains the bending of light as it passes around an obstacle or through an aperture?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Dispersion

Correct answer: C

Rationale: Diffraction is the phenomenon that explains the bending of light as it passes around an obstacle or through an aperture. When light encounters an obstacle or passes through an aperture, it diffracts, causing it to bend around the edges. Refraction, on the other hand, occurs when light passes from one medium to another, causing it to change direction. Reflection involves the bouncing back of light rays from a surface, and dispersion is the separation of light into its different colors. Therefore, the correct answer is C, as diffraction specifically addresses the bending of light as it interacts with obstacles or apertures, unlike the other choices that describe different optical phenomena.

5. Which of the following organs is part of the central nervous system?

• A. Heart
• B. Brain
• C. Liver
• D. Lungs

Correct answer: B

Rationale: The correct answer is B: Brain. The brain is a vital organ that is part of the central nervous system, along with the spinal cord. It plays a crucial role in processing information, controlling body functions, and coordinating responses to stimuli. The heart, liver, and lungs are not part of the central nervous system; they belong to the cardiovascular and respiratory systems, respectively. The heart is part of the cardiovascular system, responsible for pumping blood throughout the body. The liver is part of the digestive system, involved in processes like detoxification and metabolism. The lungs are part of the respiratory system, facilitating the exchange of oxygen and carbon dioxide during breathing.

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