HESI Exams Quizlet Physics

Correct Answer: A

Rationale: The correct answer is A: 10 m/s. Velocity is calculated by dividing the distance traveled by the time taken. In this case, velocity = 100m / 10s = 10 m/s. Choice B, 90 m/s, is incorrect because it is not the accurate calculation. Choice C, 110 m/s, and choice D, 1,000 m/s, are both incorrect as they do not align with the correct formula for calculating velocity. The key is to remember that velocity is a vector quantity that includes both speed and direction, and in this case, we are only concerned with the speed of the object, making choice A the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Permeability is preferred. High permeability in the core of an electromagnet enhances its magnetic field strength by allowing more magnetic flux to pass through, increasing the efficiency of the electromagnet. Resistivity (choice A) would hinder current flow, reducing magnetic field strength. Permittivity (choice C) is related to electric fields, not magnetic fields. Dielectric strength (choice D) is the ability of a material to withstand electric fields, not directly related to enhancing magnetic properties.

Correct Answer: B

Rationale: The drag force experienced by an object moving through a fluid depends on fluid properties (like viscosity and density) and object velocity. This is because the resistance encountered by the object is influenced by how easily the fluid can flow around it and the speed at which it moves through the fluid. The shape and size of the object can affect the drag force, but they are not the only factors determining it. The depth of submersion primarily affects buoyancy, not drag force. The buoyant force acting on the object is related to its weight and the density of the fluid, but it does not directly determine the drag force experienced by the object.

Correct Answer: A

Rationale: To calculate momentum, we use the formula p = mv, where p is momentum, m is mass, and v is velocity. Since momentum is conserved, the momentum of the 2,000-kg car is equal to the momentum of the 1,500-kg car. Setting the two momentum equations equal to each other, we get 2000*15 = 1500*v, where v is the velocity of the 1,500-kg car to generate the same momentum. Solving for v, we get v = (2000*15) / 1500 = 20 m/s. Therefore, to generate the same momentum as the 2,000-kg car, the 1,500-kg car would need to accelerate to 20 m/s. Choice A is correct. Choices B, C, and D are incorrect as changing the mass or a combination of adding mass and velocity will not lead to the 1,500-kg car generating

Correct Answer: D

Rationale: The correct answer is D: Dry ice. Dry ice is solid carbon dioxide that sublimes directly into carbon dioxide gas without melting into a liquid state. This process can be observed in everyday situations, such as when dry ice "evaporates" in a cooler. Iron (A) and Silver (B) do not undergo sublimation but instead melt into liquid phases. Salt crystal (C) also melts into a liquid (brine solution) before evaporating.