Nursing Elites

1. The speed of sound in dry air at 20°C is 343 m/s. If the wavelength of a sound wave is 5 m, what is its frequency?

• A. 171.5 Hz
• B. 79 Hz
• C. 68.6 Hz
• D. 63.6 Hz

Correct answer: C

Rationale: The speed of sound (v) can be calculated using the formula: v = f × λ, where f is the frequency and λ is the wavelength. Given that the speed of sound is 343 m/s and the wavelength is 5 m, we can rearrange the formula to solve for frequency: f = v / λ = 343 / 5 = 68.6 Hz. Therefore, the correct frequency is 68.6 Hz. Choices A, B, and D are incorrect as they do not result from the correct calculation based on the given values.

2. A lab needs 200ml of a 5% salt solution. They only have a 10% solution. How much 10% solution and water should be mixed?

• A. 100ml 10% solution, 100ml water
• B. 150ml 10% solution, 50ml water
• C. 160ml 10% solution, 40ml water
• D. 200ml 10% solution, 0ml water

Correct answer: B

Rationale: Rationale: 1. Let x be the volume of the 10% solution needed and y be the volume of water needed. 2. The total volume of the final solution is 200ml, so x + y = 200. 3. The concentration of the final solution is 5%, so the amount of salt in the final solution is 0.05 * 200 = 10g. 4. The amount of salt in the 10% solution is 0.1x, and the amount of salt in the water is 0, so the total amount of salt in the final solution is 0.1x. 5. Since the total amount of salt in the final solution is 10g, we have 0.1x = 10. 6. Solving for x, we get x = 100ml. 7. Substituting x =

3. What is the number of protons in the atomic nucleus of an alkali metal?

• A. 9
• B. 10
• C. 11
• D. 12

Correct answer: C

Rationale: The number of protons in the atomic nucleus of an alkali metal is 11. Alkali metals, belonging to group 1 of the periodic table, have 1 electron in their outer shell, which corresponds to 1 proton in their nucleus. Therefore, the correct answer is option C: 11. Choice A (9) is incorrect because it does not match the number of protons in an alkali metal. Choice B (10) is incorrect as it is also not the correct number of protons for an alkali metal. Choice D (12) is incorrect as it is not the typical number of protons found in the nucleus of an alkali metal.

4. In the scientific process, which of the following is a statement or explanation of certain events or happenings?

• A. hypothesis
• B. observation
• C. experiment
• D. conclusion

Correct answer: A

Rationale: A hypothesis is a statement or explanation of certain events or phenomena based on observations and prior knowledge. It is a testable prediction that guides the scientific investigation process. By formulating a hypothesis, scientists can make predictions and design experiments to gather data and test the validity of the hypothesis. Observations (choice B) involve gathering information through the senses. Experiments (choice C) are procedures carried out to support or refute a hypothesis. Conclusions (choice D) are deductions made based on the results of experiments and observations, but they are not the initial statement or explanation of events or happenings.

5. What is the result of adding 12 1/21 and 3 1/3?

• A. 15 8/21
• B. 16 5/24
• C. 15
• D. 14

Correct answer: A

Rationale: To add 12 1/21 and 3 1/3, first add the whole numbers: 12 + 3 = 15. Then, add the fractions: 1/21 + 1/3. To find a common denominator, multiply 21 by 3 to get 63. Convert 1/21 to an equivalent fraction with a denominator of 63 by multiplying the numerator and denominator by 3, resulting in 3/63. Now add 3/63 (equivalent to 1/21) and 21/63 (equivalent to 1/3) to get 24/63. Simplifying 24/63 gives 8/21. Therefore, the sum is 15 8/21. Choices B, C, and D are incorrect because they do not result from the correct addition of the given numbers and fractions.

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