Nursing Elites

1. Why does potential energy increase as particles approach each other?

• A. Attractive forces increase.
• B. Attractive forces decrease.
• C. Repulsive forces increase.
• D. Repulsive forces decrease.

Correct answer: C

Rationale: The correct answer is C: Repulsive forces increase. As particles approach each other, the distance between them decreases, causing the repulsive forces between the particles to increase. This increase in repulsive forces leads to an increase in potential energy as the particles resist being pushed closer together. Choices A and B are incorrect because attractive forces do not increase or decrease in this scenario. Choice D is incorrect because repulsive forces actually increase as particles get closer, leading to a rise in potential energy.

2. 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.

3. Marilyn is driving to a wedding. She drives 4 miles south before realizing that she left the gift at home. She makes a U-turn, returns home to pick up the gift, and sets out again driving south. This time, she drives 1 mile out of her way to pick up a friend. From there, they continue 5 miles more to the wedding. Which of these statements is true about Marilyn’s trip?

• A. The displacement of her trip is 6 miles, and the distance traveled is 6 miles.
• B. The displacement of her trip is 14 miles, and the distance traveled is 14 miles.
• C. The displacement of her trip is 8 miles, and the distance traveled is 14 miles.
• D. The displacement of her trip is 6 miles, and the distance traveled is 14 miles.

Correct answer: C

Rationale: Marilyn’s displacement is calculated based on her final position relative to the starting point. She drives 1 mile to pick up her friend, then 5 miles more to the wedding, totaling 6 miles after returning to her home. So, the correct displacement is 8 miles south from her starting point (4 miles to the gift + 4 miles return + 1 mile to the friend + 5 miles to the wedding). The total distance traveled is 14 miles (adding all the distances). Choice A is incorrect because it miscalculates the displacement. Choice B is incorrect as it overestimates both the displacement and distance traveled. Choice D is incorrect as it underestimates the displacement.

4. Archimedes' principle explains the ability to control buoyancy, allowing:

• A. Objects to sink regardless of density differences.
• B. Airplanes to generate lift for flight.
• C. Submarines to adjust their buoyancy for submergence and resurfacing.
• D. Helium balloons to overcome gravity and float.

Correct answer: C

Rationale: Archimedes' principle states that the upward buoyant force acting on an object submerged in a fluid is equal to the weight of the fluid displaced by the object. Submarines control their buoyancy by adjusting the volume of water they displace, which allows them to submerge and resurface. Choice C is correct because it directly relates to the principle of buoyancy and how submarines utilize it. Choices A, B, and D are incorrect because they do not accurately reflect the application of Archimedes' principle in controlling buoyancy for submergence and resurfacing.

5. 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 Nâ‹…m
• B. 6,000 Nâ‹…m
• C. 60,000 Nâ‹…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 Nâ‹…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.

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