Nursing Elites

1. A wave moves through its medium at 20 m/s with a wavelength of 4 m. What is the frequency of the wave?

• A. 5 s−1
• B. 16 s−1
• C. 24 s−1
• D. 80 s−1

Correct answer: C

Rationale: The formula to calculate the frequency of a wave is given by:

2. When a car is driven for a long time, the pressure of air in the tires increases. This is best explained by which of the following gas laws?

• A. Boyle's law
• B. Charles' law
• C. Gay-Lussac's law
• D. Dalton's law

Correct answer: C

Rationale: Gay-Lussac's law, also known as the law of pressure-temperature, states that the pressure of a gas is directly proportional to its absolute temperature when the volume is constant. As a car is driven for a long time, the tires heat up due to friction and increased air pressure inside the tires. This results in an increase in temperature, causing the pressure of the air inside the tires to increase according to Gay-Lussac's law. Choices A, B, and D are incorrect. Boyle's law relates pressure and volume, Charles' law relates volume and temperature, and Dalton's law deals with the partial pressures of gases in a mixture.

3. Which substance would be most affected by a change in temperature?

• A. Liquid nitrogen
• B. Salt crystals
• C. Hydrogen gas
• D. Iron filings

Correct answer: C

Rationale: Hydrogen gas would be most affected by a change in temperature because gases have a greater expansion or contraction in volume with changes in temperature compared to liquids or solids. When the temperature of hydrogen gas increases, its molecules gain kinetic energy and move faster, causing the gas to expand and its volume to increase. Conversely, when the temperature decreases, the gas molecules lose kinetic energy and move slower, leading to a decrease in volume. This property makes hydrogen gas highly sensitive to temperature changes compared to liquid nitrogen, salt crystals, or iron filings. Liquid nitrogen, salt crystals, and iron filings are less affected by temperature changes because their particles are closer together and have lower kinetic energy, resulting in minimal volume changes with temperature fluctuations.

4. Two balloons with charges of 5 μC each are placed 25 cm apart. What is the magnitude of the resulting repulsive force between them?

• A. 0.18 N
• B. 1.8 N
• C. 10−3 N
• D. 5 × 10−3 N

Correct answer: B

Rationale: To find the repulsive force between the two charges, we use Coulomb's law: F = k(q1 * q2) / r^2. Here, k is the Coulomb constant (8.99 x 10^9 Nm^2/C^2), q1 and q2 are the charges (5 μC each), and r is the distance between the charges (25 cm = 0.25 m). Substituting these values into the formula: F = (8.99 x 10^9 Nm^2/C^2)(5 x 10^-6 C)(5 x 10^-6 C) / (0.25 m)^2. Calculating this gives F = 1.8 N. Therefore, the magnitude of the resulting repulsive force between the two balloons is 1.8 N. Choice A, C, and D are incorrect as they do not correctly calculate the force using Coulomb's law.

5. Jack stands in front of a plane mirror. If he is 5 feet away from the mirror, how far away from Jack is his image?

• A. 2.5 feet
• B. 3 feet
• C. 4.5 feet
• D. 5 feet

Correct answer: D

Rationale: When Jack stands in front of a plane mirror, his image appears the same distance behind the mirror as Jack is in front of it. Therefore, if Jack is 5 feet away from the mirror, his image will also appear 5 feet behind the mirror. The total distance from Jack to his image is the sum of these distances, which equals 10 feet. Choices A, B, and C are incorrect because the image distance is not half of the total distance but the same as the object's distance from the mirror.

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