Nursing Elites

1. A ball is thrown horizontally off a cliff with a speed of 10 m/s. What is the horizontal distance the ball travels before hitting the ground?

• A. 10 m
• B. 20 m
• C. 30 m
• D. Cannot be determined without knowing the height of the cliff

Correct answer: C

Rationale: When a ball is thrown horizontally, its horizontal velocity remains constant throughout its motion. The horizontal distance traveled by the ball is determined by the horizontal velocity and the time taken to hit the ground. In this case, the horizontal distance is calculated as distance = velocity × time. Since the horizontal velocity is 10 m/s, the horizontal distance traveled by the ball is 10 m/s × time. The time taken to hit the ground is determined by the vertical motion, which is independent of the horizontal velocity. Therefore, without knowing the height of the cliff, we can still determine the horizontal distance traveled by the ball. The horizontal distance is solely dependent on the horizontal velocity and the time of flight, which are not influenced by the height of the cliff. Hence, the correct answer is 30 m. Choice A, 10 m, is incorrect as it does not consider the time of flight. Choice B, 20 m, is incorrect as it does not account for the constant horizontal velocity. Choice D, 'Cannot be determined without knowing the height of the cliff,' is incorrect because the horizontal distance can be calculated independently of the height of the cliff.

2. Which of the following is a common property of bases?

• A. Conductivity in aqueous solutions
• B. Sour taste
• C. Reactivity with metals to produce hydrogen gas
• D. Turns red litmus paper blue

Correct answer: D

Rationale: Bases are substances that can accept protons or donate hydroxide ions in a chemical reaction. One common property of bases is that they turn red litmus paper blue. This is a classic test to distinguish between acids (which turn blue litmus paper red) and bases. Conductivity in aqueous solutions (Option A) is a property of both acids and bases, but not unique to bases alone. Sour taste (Option B) is a property commonly associated with acids, not bases. Reactivity with metals to produce hydrogen gas (Option C) is a property of acids, particularly strong acids, but not bases.

3. What role does DNA play in evolution?

• A. It stores genetic information that can be passed on to offspring.
• B. It allows for mutations that can introduce new variations.
• C. It regulates the expression of genes that influence traits.
• D. All of the above

Correct answer: D

Rationale: A) DNA stores genetic information that is passed on from parents to offspring through the process of reproduction. This genetic information contains instructions for the development and functioning of an organism. It serves as the hereditary material that carries the blueprint for an organism's traits and characteristics, allowing for the transmission of genetic information from one generation to the next. B) DNA can undergo mutations, which are changes in the genetic sequence. These mutations can introduce new variations in the DNA, leading to genetic diversity within a population. These variations are essential for natural selection and adaptation to changing environments. C) DNA plays a crucial role in regulating the expression of genes. Gene expression determines which proteins are produced in an organism, influencing its traits and characteristics. By controlling gene expression, DNA contributes to the development and maintenance of an organism's traits. D) Therefore, DNA is involved in all of the above processes, making it a key factor in evolution by driving genetic variation, inheritance, and gene expression. The interplay of these functions allows for the diversity and adaptation of species over time, shaping the evolutionary process.

4. Which gas is the most abundant in Earth's atmosphere?

• A. Nitrogen
• B. Oxygen
• C. Carbon dioxide
• D. Argon

Correct answer: A

Rationale: Nitrogen is the most abundant gas in Earth's atmosphere, constituting approximately 78% of the air we breathe. It is essential for various biological processes, including plant growth and nitrogen fixation. Moreover, nitrogen is a key component of the greenhouse effect, playing a crucial role in regulating the planet's temperature. Oxygen, while important for respiration, comprises about 21% of the atmosphere. Carbon dioxide, though vital for photosynthesis and a greenhouse gas, is present in much lower concentrations than nitrogen. Argon, an inert gas, is a minor component of the atmosphere.

5. Why is the electrical conductivity of a strong acid solution higher than that of a weak acid solution?

• A. Strong acids are more concentrated.
• B. Strong acids release more hydrogen ions.
• C. Weak acids are better at dissolving salts.
• D. Strong acids have a lower pH.

Correct answer: B

Rationale: The correct answer is B because strong acids release more hydrogen ions compared to weak acids. This higher concentration of ions in the solution leads to a higher electrical conductivity. Strong acids ionize completely in solution, producing a higher concentration of ions that can conduct electricity, whereas weak acids only partially ionize, resulting in a lower concentration of ions and lower electrical conductivity. Choice A is incorrect because the concentration of the acid does not directly determine its electrical conductivity. Choice C is incorrect as the ability to dissolve salts is not directly related to electrical conductivity. Choice D is incorrect because the pH of the solution, although related to acidity, does not directly determine the electrical conductivity.

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