Nursing Elites

1. During an isothermal (constant temperature) expansion, what is the work done by the gas on the surroundings?

• A. Positive and equal to the change in internal energy.
• B. Zero.
• C. Negative and equal to the change in internal energy.
• D. Positive and greater than the change in internal energy.

Correct answer: D

Rationale: In an isothermal expansion, the temperature remains constant, meaning there is no change in internal energy. However, the gas still does work on the surroundings as it expands, and this work is positive. Since internal energy does not change, the correct answer is D, 'Positive and greater than the change in internal energy.' Choice A is incorrect because the work done is not equal to the change in internal energy. Choice B is incorrect as work is done during the expansion. Choice C is incorrect since the work done is not negative during an isothermal expansion.

2. 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:

3. As a car is traveling on the highway, its speed drops from 60 mph to 30 mph. What happens to its kinetic energy?

• A. Its energy is halved.
• B. Its energy is doubled.
• C. Its energy is quadrupled.
• D. Its energy is divided by four.

Correct answer: A

Rationale: The correct answer is A. Kinetic energy is proportional to the square of the velocity. When the speed drops from 60 mph to 30 mph, the kinetic energy is halved. Choice B is incorrect because halving the speed results in halving the kinetic energy, not doubling it. Choice C is incorrect because quadrupling the kinetic energy would require increasing the speed fourfold, not halving it. Choice D is incorrect because dividing the energy by four would imply a different relationship between speed and kinetic energy, which is not the case.

4. In a static fluid, pressure (P) at a depth (h) is governed by the hydrostatic equation:

• A. P = ρgh
• B. P = γh
• C. P = μgh
• D. P = bh

Correct answer: A

Rationale: The correct formula for the pressure at a certain depth in a fluid according to the hydrostatic equation is P = ρgh. Here, ρ represents the fluid's density, g is the gravitational acceleration, and h is the depth. This formula shows that pressure increases linearly with the density of the fluid, the acceleration due to gravity, and the depth. Choices B, C, and D are incorrect because they do not accurately represent the relationship between pressure, density, gravitational acceleration, and depth in a static fluid.

5. Bernoulli's principle for an incompressible, inviscid fluid in steady flow states that the mechanical energy, consisting of:

• A. Pressure (P) only, remains constant along a streamline.
• B. Velocity (v) only, remains constant along a streamline.
• C. P + ½ρv² (total mechanical energy), remains constant along a streamline
• D. Density (ρ) only, remains constant along a streamline.

Correct answer: C

Rationale: Bernoulli's principle states that the sum of pressure energy (P), kinetic energy per unit volume (½ρv²), and potential energy per unit volume remains constant along a streamline in an incompressible, inviscid fluid. This means the total mechanical energy of the fluid is conserved, making Choice C the correct answer. Choices A, B, and D are incorrect because Bernoulli's principle involves the conservation of the total mechanical energy, not just pressure, velocity, or density alone.

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