Nursing Elites

1. Sublimation is the change in matter from solid to gas or gas to solid without passing through a liquid phase. Outside of the laboratory, which solid provides the best example of this?

• A. Iron
• B. Silver
• C. Salt crystal
• D. Dry ice

Correct answer: D

Rationale: Dry ice (solid carbon dioxide) provides the best example of sublimation outside of the laboratory. When dry ice is exposed to normal atmospheric conditions, it changes directly from a solid to a gas without passing through a liquid phase. This process is commonly observed in everyday situations such as creating 'smoke' or 'fog' effects. Choices A, B, and C (Iron, Silver, and Salt crystal) do not undergo sublimation. Iron and Silver melt and then vaporize, while Salt crystal dissolves in water, and the resulting solution evaporates, which involves a liquid phase.

2. If the force acting on an object is doubled, how does its acceleration change?

• A. It remains the same.
• B. It is halved.
• C. It is doubled.
• D. It is eliminated.

Correct answer: C

Rationale: According to Newton's second law of motion, the acceleration of an object is directly proportional to the force acting on it. Therefore, if the force acting on an object is doubled, its acceleration will also double. This relationship is expressed by the equation F = ma, where F is the force, m is the mass of the object, and a is the acceleration. When the force (F) is doubled, the acceleration (a) will also double, assuming the mass remains constant. Choice A is incorrect because acceleration changes with a change in force. Choice B is incorrect because acceleration and force are directly proportional. Choice D is incorrect because increasing the force acting on an object does not eliminate its acceleration; instead, it results in an increase in acceleration, as per Newton's second law.

3. A plucked guitar string makes 80 vibrations in one second. What is the period?

• A. 0.0125 s
• B. 0.025 s
• C. 0.125 s
• D. 0.25 s

Correct answer: B

Rationale: The period is the time taken for one complete vibration of the guitar string. To find the period, you need to take the reciprocal of the frequency. Since the string makes 80 vibrations in one second, the period is 1/80 = 0.0125 seconds (or 0.025 s). Choice A is incorrect because it is the reciprocal of 80. Choice C is incorrect as it is 10 times the reciprocal of 80. Choice D is incorrect as it is 100 times the reciprocal of 80.

4. What is the diameter of a loop if its radius is 6 meters?

• A. 6 m
• B. 12 m
• C. 18 m
• D. 36 m

Correct answer: B

Rationale: The diameter of a loop is calculated by multiplying the radius by 2. Since the radius is 6 meters, the diameter is 6 × 2 = 12 meters. Therefore, the correct answer is 12 meters. Choice A (6 m) is the radius, not the diameter. Choices C (18 m) and D (36 m) are incorrect as they do not reflect the correct calculation for determining the diameter of a loop.

5. A 2,000-kg car travels at 15 m/s. For a 1,500-kg car traveling at 15 m/s to generate the same momentum, what would need to happen?

• A. It would need to accelerate to 20 m/s.
• B. It would need to add 500 kg in mass.
• C. Both A and B
• D. Either A or B

Correct answer: A

Rationale: Momentum is calculated as the product of mass and velocity. Since momentum is conserved in the absence of external forces, for the 1,500-kg car to generate the same momentum as the 2,000-kg car at 15 m/s, it would need to increase its velocity to compensate for the difference in mass. Accelerating to 20 m/s would achieve this without needing to change the mass of the car. Choice B is incorrect because adding mass is not necessary to match momentum in this scenario.

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