HESI A2 Physics

Correct Answer: D

Rationale: The correct answer is D: Kinetic energy. Potential energy is the energy stored in an object due to its position or state. As the vehicle rolls downhill, potential energy decreases while kinetic energy, the energy of motion, increases. This transformation occurs as the vehicle gains speed and moves due to the force of gravity. The other choices are incorrect because thermal energy is not directly related to the motion of the vehicle in this scenario, and the transformation does not involve a combination of thermal and kinetic energy. The vehicle's movement downhill is primarily a conversion of potential energy into kinetic energy.

Correct Answer: A

Rationale: To determine the velocity of a wave, you need to use the formula v = fλ, where v is the velocity, f is the frequency, and λ is the wavelength. By multiplying the frequency by the wavelength (option A), you are essentially applying the correct formula for calculating wave velocity. This is because the velocity of a wave is directly proportional to both its frequency and wavelength. Option B (adding the frequency and wavelength) and Option C (subtracting the wavelength from the frequency) do not align with the correct formula for wave velocity calculation, as it involves multiplication rather than addition or subtraction. Option D (dividing the wavelength by the frequency) is also incorrect because the correct operation for determining wave velocity is multiplication, not division.

Correct Answer: C

Rationale: Rationale: 1. Speed of sound in a fluid depends on its bulk modulus, which measures the fluid's resistance to compression. 2. Density affects how closely packed the molecules are, influencing the speed of sound propagation. 3. Viscosity and surface tension do not directly affect the speed of sound in a fluid. 4. Choice C is correct as both density and bulk modulus are crucial factors in determining the speed of sound in a compressible fluid.

Correct Answer: C

Rationale: The correct answer is C because in a cyclic process, the system returns to its initial state, so the net work done over the entire cycle can be positive, negative, or zero depending on the path taken. If the system undergoes a clockwise cycle on a PV diagram, work is done by the system (positive Wnet). If the cycle is counterclockwise, work is done on the system (negative Wnet). If the cycle is a closed loop, the net work done can be zero. Choices A and B are incorrect because they are too absolute and do not consider the different possibilities in a cyclic process. Choice D is incorrect because the net work done is not necessarily equal to the total heat transferred; it depends on the specific process and path taken.

Correct Answer: A

Rationale: The correct answer is A: 5 miles per hour due southwest. A vector quantity has both magnitude and direction, which is represented by the speed (5 miles per hour) and the direction (southwest). This choice clearly indicates both aspects. Explanation for why the other choices are incorrect: - B: 5 miles per hour: This choice only provides the magnitude of the quantity (speed) without indicating any direction. - C: 5 miles: This choice only provides the magnitude (distance) without any indication of direction. - D: None of the above: This choice dismisses all options without providing the correct representation of a vector quantity with both magnitude and direction.