Nursing Elites

1. The average life expectancy at birth in the United States at the beginning of the 21st century was about 75 years. The average life expectancy at birth in the middle of the 19th century was only about 40 years. Which of the following factors are likely to have contributed to the longer life expectancy in the 21st century? (Select the one that does not apply)

• A. The human body has evolved to become more resilient to its environment.
• B. There have been numerous advances in medical technology and treatments.
• C. Higher standards of basic cleanliness have helped people avoid illness.
• D. The creation of vaccines has nearly eliminated certain diseases that were once deadly.

Correct answer: A

Rationale: Medical advances, higher standards of cleanliness, and the creation of vaccines have all significantly contributed to the increase in life expectancy over time. While human evolution plays a role in adaptation to the environment over millennia, it is not a primary factor that has led to the substantial increase in life expectancy within a few centuries. The human body's evolution is a slow process that occurs over generations, while the advancements in medical technology, cleanliness, and vaccines have had a more immediate and direct impact on improving life expectancy.

2. What is the name of a condition where the immune system mistakenly attacks healthy body tissues?

• A. Allergy
• B. Autoimmune disease
• C. Immunodeficiency
• D. Sepsis

Correct answer: B

Rationale: Autoimmune diseases occur when the immune system mistakenly targets and attacks healthy body tissues, leading to inflammation and damage. This results in conditions such as rheumatoid arthritis, lupus, and type 1 diabetes. Allergies, on the other hand, involve an exaggerated immune response to harmless substances like pollen or certain foods. Immunodeficiency refers to a weakened immune system, making individuals more susceptible to infections. Sepsis is a severe systemic response to an infection, leading to organ dysfunction and potentially life-threatening complications.

3. How many grams of solid CaCO3 are needed to make 600 mL of a 35 M solution? The atomic masses for the elements are as follows: Ca = 40.1 g/mol; C = 12.01 g/mol; O = 16.00 g/mol.

• A. 18.3 g
• B. 19.7 g
• C. 21.0 g
• D. 24.2 g

Correct answer: B

Rationale: 1. First, calculate the molar mass of CaCO3 by adding the atomic masses of Ca, C, and 3 O atoms: 40.1 + 12.01 + (3 * 16.00) = 100.13 g/mol. 2. Calculate the number of moles in 600 mL of a 35 M solution: 600 mL * 35 mol/L = 21,000 mmol. 3. Convert moles to grams using the molar mass of CaCO3: 21,000 mmol * (100.13 g/mol / 1000 mmol/mol) = 2,102.73 g. 4. Therefore, you would need 19.7 g of solid CaCO3 to make 600 mL of a 35 M solution.

4. What property of a wave determines its pitch in sound waves?

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

Correct answer: B

Rationale: The pitch of a sound wave is determined by its frequency. Frequency is the number of cycles of a wave that occur in a given time period. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. Amplitude refers to the intensity or loudness of a sound wave, wavelength is the distance between two consecutive points in a wave, and speed is the rate at which a wave travels through a medium. Therefore, in sound waves, it is the frequency that primarily determines the pitch, making option B the correct answer.

5. What force keeps a car moving along a curved road?

• A. Gravitational force
• B. Normal force from the road
• C. Air resistance
• D. Friction between the tires and the road

Correct answer: D

Rationale: The correct answer is D: Friction between the tires and the road. When a car travels along a curved road, the friction between the tires of the car and the road provides the necessary centripetal force required to keep the car moving in the curved path. This friction allows the tires to grip the road and prevent the car from sliding off the curve due to inertia or momentum. Choices A, B, and C are incorrect because gravitational force, normal force from the road, and air resistance do not play a significant role in keeping a car moving along a curved road. While these forces may have other effects on the car's motion, they are not the primary force responsible for maintaining the car's trajectory along a curve.

Similar Questions