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. Amanda uses 100 N of force to push a lawnmower around her lawn. If she mows 20 rows measuring 30 meters each, how much work does she do?

• A. 3,000 N⋅m
• B. 6,000 N⋅m
• C. 60,000 N⋅m
• D. The answer cannot be determined from the information given.

Correct answer: C

Rationale: The work done by Amanda pushing the lawnmower is calculated by multiplying the force applied (100 N) by the distance over which the force is applied (the total distance mowed). Since Amanda mows 20 rows, each measuring 30 meters, the total distance mowed is 20 rows x 30 meters/row = 600 meters. Therefore, the work done is 100 N x 600 m = 60,000 N⋅m. Option A and B are incorrect as they do not account for the total distance mowed. Option D is incorrect as the work done can be accurately calculated based on the information provided.

3. What is the net force acting on the car?

• A. 450 N
• B. 700 N
• C. 1,500 N
• D. 6,300 N

Correct answer: C

Rationale: To determine the net force acting on an object, we need to consider the sum of the forces acting in the same direction and subtract the forces acting in the opposite direction. In this scenario, there is a force of 4,200 N to the right and a force of 2,700 N to the left. By subtracting the leftward force from the rightward force (4,200 N - 2,700 N), we find that the net force acting on the car is 1,500 N to the right. Therefore, choice C, 1,500 N, is the correct answer. Choice A, 450 N, is too small as it does not account for the total forces involved. Choice B, 700 N, is also incorrect as it is not the result of the correct mathematical operation on the given forces. Choice D, 6,300 N, is too large and does not align with the calculation based on the forces provided.

4. A concave mirror with a focal length of 2 cm forms a real image of an object at an image distance of 6 cm. What is the object's distance from the mirror?

• A. 3 cm
• B. 6 cm
• C. 12 cm
• D. 30 cm

Correct answer: B

Rationale: The mirror formula, 1/f = 1/do + 1/di, can be used to solve for the object distance. Given that the focal length (f) is 2 cm and the image distance (di) is 6 cm, we can substitute these values into the formula to find the object distance. Plugging in f = 2 cm and di = 6 cm into the formula gives us 1/2 = 1/do + 1/6. Solving for do, we get do = 6 cm. Therefore, the object's distance from the mirror is 6 cm. Choice A (3 cm), Choice C (12 cm), and Choice D (30 cm) are incorrect distances as the correct object distance is determined to be 6 cm.

5. What does Coulomb’s law relate to?

• A. electrostatic interaction
• B. rigid body motion
• C. heat conduction
• D. universal gravitation

Correct answer: A

Rationale: Coulomb's law is a fundamental principle in physics that deals with the electrostatic interaction between charged particles. It states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. This law is crucial in understanding and predicting the behavior of electrically charged objects. Choices B, C, and D are incorrect because Coulomb's law specifically focuses on electrostatic interactions between charges, not rigid body motion, heat conduction, or universal gravitation.

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