Nursing Elites

1. An object with a mass of 45 kg has momentum equal to 180 kg⋅m/s. What is the object’s velocity?

• A. 4 m/s
• B. 8.1 km/s
• C. 17.4 km/h
• D. 135 m/s

Correct answer: A

Rationale: The momentum of an object is calculated by multiplying its mass and velocity. Mathematically, momentum = mass x velocity. Given that the mass is 45 kg and the momentum is 180 kgâ‹…m/s, we can rearrange the formula to solve for velocity: velocity = momentum / mass. Plugging in the values, velocity = 180 kgâ‹…m/s / 45 kg = 4 m/s. Therefore, the object's velocity is 4 m/s. Choices B, C, and D are incorrect because they do not align with the correct calculation based on the given mass and momentum values.

2. When a crane hoists a massive object at a constant velocity compared to lifting the same object gradually, the work done by the crane is:

• A. Less
• B. More
• C. Identical
• D. Dependent on the object's mass

Correct answer: C

Rationale: The work done by the crane is identical in both scenarios. Work is defined as the force applied over a distance. Since the force needed to lift the object is equal to its weight and the displacement is the same, the work done is identical, whether the object is lifted gradually or at a constant velocity. Choice A is incorrect because the work done is the same in both cases. Choice B is incorrect as well since the work done does not increase. Choice D is incorrect as the mass of the object does not affect the work done by the crane in this scenario.

3. Which of these objects has the greatest momentum?

• A. A 1,250-kg car moving at 5 m/s
• B. An 80-kg person running at 4 m/s
• C. A 10-kg piece of meteorite moving at 600 m/s
• D. A o.5-kg rock moving at 40 m/s

Correct answer: A

Rationale: Momentum is the product of mass and velocity. The car has the highest momentum because it has the largest mass and a significant velocity.

4. Four 5 V batteries are connected in series. What is the total voltage of the circuit?

• A. 5.0 V
• B. 10.0 V
• C. 15.0 V
• D. 20.0 V

Correct answer: D

Rationale: When batteries are connected in series, their voltages add up. Therefore, the total voltage of the circuit with four 5 V batteries connected in series will be 5 V + 5 V + 5 V + 5 V = 20 V. Choices A, B, and C are incorrect because the voltages of the batteries add up in series, resulting in a total of 20 V.

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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