Nursing Elites

1. What happens to the potential energy of an object as it falls freely near the Earth's surface?

• A. Potential energy decreases
• B. Potential energy increases
• C. Potential energy remains constant
• D. Potential energy becomes zero

Correct answer: A

Rationale: As an object falls freely near the Earth's surface, its potential energy decreases. This decrease occurs because the gravitational potential energy is being converted into kinetic energy as the object accelerates due to gravity. According to the law of conservation of energy, the total mechanical energy (the sum of potential and kinetic energy) remains constant in the absence of non-conservative forces like air resistance. Choice B ('Potential energy increases') is incorrect because the object's potential energy is being converted into kinetic energy, leading to a decrease. Choice C ('Potential energy remains constant') is incorrect as the conversion of potential energy to kinetic energy results in a decrease in potential energy. Choice D ('Potential energy becomes zero') is incorrect because potential energy is not reduced to zero but is transformed into kinetic energy as the object falls.

2. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?

• A. Molality (m)
• B. Molarity (M)
• C. Weight percent (%)
• D. Parts per million (ppm)

Correct answer: A

Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.

3. What are the three layers of the skin?

• A. Epidermis, dermis, subdermis
• B. Epidermis, dermis, hypodermis
• C. Dermis, subdermis, hypodermis
• D. Epidermis, dermis, adipose layer

Correct answer: B

Rationale: The correct answer is B: Epidermis, dermis, hypodermis. The three layers of the skin are the epidermis (outer layer), dermis (middle layer), and hypodermis (inner layer of fat and connective tissue). The hypodermis is also known as the subcutaneous tissue and is primarily composed of adipose (fat) tissue, providing insulation and padding to the body. Choice A is incorrect as 'subdermis' is not a recognized layer of the skin. Choice C is incorrect as 'dermis' is the middle layer, not the outer layer. Choice D is incorrect as the layer below the dermis is the hypodermis, not specifically an 'adipose layer.'

4. Which term describes the resistance of a substance to flow?

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

Correct answer: B

Rationale: Viscosity is the term used to describe the resistance of a substance to flow. It quantifies how thick or thin a fluid is and how easily it flows. Density (A) refers to the mass of a substance per unit volume and does not directly relate to resistance to flow. Conductivity (C) is the property of a material to conduct electricity or heat, not related to resistance to flow. Malleability (D) is the property of a material to be hammered or rolled into thin sheets, which is not related to resistance to flow.

5. What property of a wave determines its loudness in sound waves?

• A. Amplitude
• B. Wavelength
• C. Frequency
• D. Speed

Correct answer: A

Rationale: The correct answer is Amplitude. Amplitude is the property of a wave that determines its loudness in sound waves. The greater the amplitude of a sound wave, the louder the sound will be perceived. Wavelength and frequency are related to the pitch of the sound, with wavelength affecting the tone quality and frequency determining the pitch. Speed, on the other hand, is a characteristic of how fast the wave travels through a medium and does not directly influence the loudness of the sound.

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