Nursing Elites

1. A car is moving in a circle at a constant speed. Which of the following is NOT true about its motion?

• A. It has a constant centripetal acceleration
• B. Its tangential velocity remains constant
• C. It experiences a force directed towards the center of the circle
• D. It covers the same distance in equal time intervals along its circular path

Correct answer: B

Rationale: In circular motion at a constant speed, the car has a constant centripetal acceleration (choice A), experiences a force directed towards the center of the circle (choice C), and covers the same distance in equal time intervals along its circular path (choice D). However, the tangential velocity of an object in circular motion at a constant speed changes continuously as it moves around the circle, so it is not constant (choice B). The change in tangential velocity allows the car to maintain its motion in a circular path despite moving at a constant speed. Choice A is incorrect because centripetal acceleration is indeed present to keep the car moving in a circular path. Choice C is incorrect as a force towards the center is required to keep the car in circular motion. Choice D is incorrect because the car covers equal distances in equal time intervals to maintain its circular trajectory.

2. What property best describes the characteristic that nuclear forces are much stronger than electromagnetic forces at the nuclear level?

• A. Short-range interaction
• B. Long-range interaction
• C. Repulsive force
• D. Dependent on charge only

Correct answer: A

Rationale: The correct answer is A: Short-range interaction. Nuclear forces are much stronger than electromagnetic forces at the nuclear level because they are short-range interactions that act over distances on the order of the size of an atomic nucleus. This short-range nature of nuclear forces allows them to be much stronger than the long-range electromagnetic forces, which weaken with distance according to the inverse square law. Choice B, long-range interaction, is incorrect because nuclear forces are short-range. Choice C, repulsive force, is incorrect as nuclear forces include both attractive and repulsive components. Choice D, dependent on charge only, is incorrect because nuclear forces are not solely determined by charge but also involve other factors like spin and isospin.

3. Which property of a substance resists a change in its shape?

• A. Density
• B. Mass
• C. Inertia
• D. Elasticity

Correct answer: D

Rationale: Elasticity refers to a material's ability to resist deformation and return to its original shape after stress is applied. It is the property that resists a change in shape. Density is the mass per unit volume of a substance. Mass is the amount of matter in an object, while inertia is the tendency of an object to resist changes in its state of motion. Viscosity, not mentioned in the question, is the resistance of a fluid to flow, not shape change.

4. What generates action potentials, the all-or-nothing electrical signals traveling along neurons?

• A. Glucose
• B. Sodium and potassium ions
• C. Neurotransmitters
• D. Myelin

Correct answer: B

Rationale: Action potentials, the all-or-nothing electrical signals traveling along neurons, are generated by the movement of sodium and potassium ions across the neuronal membrane. This movement creates changes in the membrane potential, leading to the propagation of the electrical signal along the neuron. Glucose is a source of energy for neurons but is not directly involved in generating action potentials. Neurotransmitters are involved in communication between neurons but do not directly generate action potentials. Myelin is a fatty substance that insulates and speeds up the conduction of action potentials but does not generate them.

5. Which of the following is the MOST common symptom of angina pectoris, a condition related to insufficient blood flow to the heart?

• A. Fever and chills.
• B. Chest pain or discomfort.
• C. Sudden onset of severe shortness of breath.
• D. Numbness or tingling in the extremities.

Correct answer: B

Rationale: Chest pain or discomfort is the most common symptom of angina pectoris. This pain is often described as squeezing, pressure, heaviness, tightness, or pain in the chest. Fever and chills, sudden onset of severe shortness of breath, and numbness or tingling in the extremities are not typical symptoms of angina pectoris. The pain associated with angina is usually triggered by physical or emotional stress and typically subsides with rest or medication, distinguishing it from other conditions.

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