Nursing Elites

1. Which factor most significantly affects the kinetic energy of an object?

• A. The object's mass
• B. The object's velocity
• C. The object's displacement
• D. The object's potential energy

Correct answer: B

Rationale: Kinetic energy is directly proportional to the square of an object's velocity. This means that changes in velocity have a greater impact on the kinetic energy of an object compared to changes in mass, displacement, or potential energy. The mass of an object affects its kinetic energy, but the effect is linear, not squared like velocity. Displacement does not directly affect kinetic energy, as it is a measure of the change in position, not related to motion. Potential energy is a different form of energy and is not directly related to the kinetic energy of an object. Therefore, the velocity of an object has the most significant effect on its kinetic energy.

2. Which type of cells make up the myelin sheaths?

• A. Glial cells.
• B. Dendrites.
• C. Melanocytes.
• D. Squamous cells.

Correct answer: A

Rationale: The correct answer is A: Glial cells. Glial cells are responsible for producing the myelin sheaths that surround and insulate nerve cells in the central and peripheral nervous systems. Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system are types of glial cells that form the myelin sheaths. Choice B, dendrites, are not involved in forming myelin sheaths; they are extensions of neurons that receive signals. Choice C, melanocytes, are cells responsible for producing melanin, not myelin. Choice D, squamous cells, are flat epithelial cells found in various tissues but are not involved in myelin sheath formation.

3. Define 'friction' in terms of opposing motion.

• A. A force that increases motion
• B. A force that accelerates motion
• C. A force that opposes motion
• D. A force that creates motion

Correct answer: C

Rationale: Friction is a force that opposes motion. When two surfaces are in contact, friction acts in the opposite direction to the motion or the potential motion between the two surfaces. It resists the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Friction hinders or prevents motion rather than promoting it. Choices A, B, and D are incorrect as they suggest that friction increases, accelerates, or creates motion, which is inaccurate. The correct definition of friction is that it opposes motion, making choice C the most appropriate option.

4. In which units is the speed of light in a vacuum measured?

• A. Meters per second
• B. Hertz
• C. Candela
• D. Newton

Correct answer: A

Rationale: The speed of light in a vacuum is commonly measured in units of meters per second. This is because the speed of light is approximately 299,792,458 meters per second in a vacuum, as defined by the International System of Units (SI). The speed of light is a measure of distance covered by light in a given time, hence it is expressed in meters per second. Choices B, C, and D are incorrect. Hertz is a unit of frequency, Candela is a unit of luminous intensity, and Newton is a unit of force. None of these units are relevant for measuring the speed of light, making 'Meters per second' the correct unit of measurement for the speed of light.

5. Which property of a substance refers to its ability to be stretched into thin wires without breaking?

• A. Conductivity
• B. Viscosity
• C. Ductility
• D. Malleability

Correct answer: C

Rationale: Ductility is the property of a substance that allows it to be stretched into thin wires without breaking. This property is distinct from the other options provided. Conductivity refers to the ability to conduct electricity or heat, viscosity refers to a liquid's resistance to flow, and malleability refers to the ability of a substance to be hammered or rolled into thin sheets. Therefore, the correct answer is 'Ductility.'

Similar Questions