HESI A2
HESI A2 Physics
1. An object with a charge of 4 μC is placed 1 meter from another object with a charge of 2 μC. What is the magnitude of the resulting force between the objects?
- A. 0.04 N
- B. 0.072 N
- C. 80 N
- D. 8 × 10−6 N
Correct answer: A
Rationale: To find the magnitude of the resulting force between two charges, we can use Coulomb's law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. The formula for Coulomb's law is: F = k × (|q1 × q2| / r²), where F is the force, k is the Coulomb constant, q1 and q2 are the charges, and r is the distance between the charges. Substituting the given values into the formula: F = (9 × 10⁹ N·m²/C²) × ((4 × 10⁻⁶ C) × (2 × 10⁻⁶ C) / (1 m)²) = 0.04 N. Therefore, the magnitude of the resulting force between the objects is 0.04 N.
2. 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.
3. How do a scalar quantity and a vector quantity differ?
- A. A scalar quantity has both magnitude and direction, and a vector does not.
- B. A scalar quantity has direction only, and a vector has only magnitude.
- C. A vector has both magnitude and direction, and a scalar quantity has only magnitude.
- D. A vector has only direction, and a scalar quantity has only magnitude.
Correct answer: C
Rationale: The correct answer is C. The main difference between a scalar quantity and a vector quantity lies in the presence of direction. A vector quantity has both magnitude and direction, while a scalar quantity has magnitude only, without any specified direction. Examples of scalar quantities include distance, speed, temperature, and energy, whereas examples of vector quantities include displacement, velocity, force, and acceleration. Choices A, B, and D are incorrect because they incorrectly describe the characteristics of scalar and vector quantities.
4. In hydraulic systems, Pascal's principle states that a pressure change applied to a confined incompressible fluid is:
- A. Amplified but loses energy
- B. Transmitted undiminished throughout the fluid
- C. Limited by the container size
- D. Dependent on the fluid type
Correct answer: B
Rationale: Pascal's principle states that when a pressure change is applied to a confined incompressible fluid, the resulting pressure change is transmitted undiminished throughout the fluid. This means that the pressure change will be the same at every point in the fluid, regardless of the container size or the type of fluid used. Therefore, choice B is the correct answer. Choices A, C, and D are incorrect because Pascal's principle specifically emphasizes the transmission of pressure without amplification, limitation by container size, or dependence on the fluid type.
5. 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.
Similar Questions
Access More Features
HESI A2 Basic
$89/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$129.99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access