HESI A2 Physics

Correct Answer: B

Rationale: The correct answer is B: The bicycle has less kinetic energy than the car. Kinetic energy is calculated as KE = 0.5 * mass * velocity^2. Since both vehicles are traveling at the same speed, the one with greater mass (the car) will have more kinetic energy. The bicycle, being lighter than the car, will have less kinetic energy despite moving at the same speed. Other choices are incorrect because A is false as explained, C is incorrect as the vehicles have different masses, and D is incorrect as both vehicles are in motion, so both have 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: D

Rationale: The correct answer is D: Cannot be created or destroyed. According to the law of conservation of energy, energy can neither be created nor destroyed, but only transformed from one form to another. This principle is a fundamental law of physics known as the first law of thermodynamics. Any process involving energy transfer must adhere to this law. Choices A, B, and C are incorrect because they contradict this fundamental principle. Energy cannot be created out of nothing or disappear completely; it can only change forms.

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 when the box falls, it converts its potential energy (due to its height above the floor) into kinetic energy (due to its motion). As it falls, its potential energy decreases while its kinetic energy increases. Therefore, the box has both kinetic and potential energy after it falls. A is incorrect because the box still has kinetic energy after hitting the floor. B is incorrect because the box gains kinetic energy as it falls. D is incorrect because the box retains some kinetic energy even after hitting the floor.