Nursing Elites

1. An object with a mass of 45 kg has momentum equal to 180 kg⋅m/s. What is the object’s velocity?

• A. 4 m/s
• B. 8.1 km/s
• C. 17.4 km/h
• D. 135 m/s

Correct answer: A

Rationale: The momentum of an object is calculated by multiplying its mass and velocity. Mathematically, momentum = mass x velocity. Given that the mass is 45 kg and the momentum is 180 kg⋅m/s, we can rearrange the formula to solve for velocity: velocity = momentum / mass. Plugging in the values, velocity = 180 kg⋅m/s / 45 kg = 4 m/s. Therefore, the object's velocity is 4 m/s. Choices B, C, and D are incorrect because they do not align with the correct calculation based on the given mass and momentum values.

2. When two long, parallel wires carry currents in the same direction, the wires will experience a force of:

• A. An unpredictable force depending on wire material
• B. Repulsion
• C. No force
• D. Attraction

Correct answer: D

Rationale: When two wires carry current in the same direction, they create magnetic fields that interact with each other. This interaction results in an attractive force between the wires due to the alignment of their magnetic fields. Choice A is incorrect because the force can be predicted based on the direction of the currents and the magnetic fields produced. Choice B is incorrect because when currents flow in the same direction, they do not repel each other. Choice C is incorrect because there is indeed a force present due to the interaction of magnetic fields, resulting in attraction between the wires.

3. Which property of a substance does not change with a change in temperature?

• A. Mass
• B. Volume
• C. Phase
• D. Solubility

Correct answer: A

Rationale: Mass is an intrinsic property of a substance that remains constant regardless of temperature changes. It is a measure of the amount of matter in an object, and this quantity does not vary with temperature or the environment in which the substance is located. The conservation of mass in chemistry dictates that mass is neither created nor destroyed, making it independent of temperature variations.\nVolume, on the other hand, changes with temperature due to thermal expansion or contraction. Phase can change with temperature, leading to transitions between solid, liquid, and gas states. Solubility is affected by temperature changes as it influences the ability of a substance to dissolve in a solvent.

4. The specific heat capacity (c) of a material is the amount of heat transfer (Q) required to raise the temperature (ΔT) of a unit mass (m) of the material by one degree (typically Celsius). The relationship between these quantities is described by the equation:

• A. Q = cΔT
• B. Q = mcΔT
• C. Q = c / mΔT
• D. Q = ΔT / mc

Correct answer: A

Rationale: The correct equation relating heat transfer (Q), mass (m), specific heat capacity (c), and change in temperature (ΔT) is Q = mcΔT. This equation states that the heat transfer is equal to the product of the mass, specific heat capacity, and temperature change. Therefore, the correct answer is B, as it correctly represents this relationship. Choices C and D do not correctly represent the relationship between these quantities and are therefore incorrect.

5. How do you determine the velocity of a wave?

• A. Multiply the frequency by the wavelength.
• B. Add the frequency and the wavelength.
• C. Subtract the wavelength from the frequency.
• D. Divide the wavelength by the frequency.

Correct answer: A

Rationale: The velocity of a wave can be determined by multiplying the frequency of the wave by the wavelength. This relationship is given by the formula: velocity = frequency × wavelength. By multiplying the frequency by the wavelength, you can calculate the speed at which the wave is traveling. This formula is derived from the basic wave equation v = f × λ, where v represents velocity, f is frequency, and λ is wavelength. Therefore, to find the velocity of a wave, one must multiply its frequency by its wavelength. Choices B, C, and D are incorrect. Adding, subtracting, or dividing the frequency and wavelength does not yield the correct calculation for wave velocity. The correct formula for determining wave velocity is to multiply the frequency by the wavelength.

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