HESI Exams Quizlet Physics

Correct Answer: C

Rationale: The correct answer is C because a vector quantity has both magnitude and direction, such as velocity, while a scalar quantity only has magnitude, like speed. A scalar quantity can be represented by a single numerical value, whereas a vector requires both a numerical value and a specific direction to fully describe it. Choices A, B, and D are incorrect because they misrepresent the defining characteristics of scalar and vector quantities. Choice A is incorrect because a vector quantity does have direction. Choice B is incorrect because it states that a scalar quantity has direction, which is inaccurate. Choice D is incorrect because it states that a scalar quantity has direction, which is also inaccurate.

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: C

Rationale: The correct answer is C: 49 N/cm. To calculate the spring constant, we use Hooke's Law: F = kx, where F is the force applied, k is the spring constant, and x is the displacement from equilibrium. Given F = mg (mass multiplied by gravity) and x = 10 cm = 0.1 m, we can solve for k: k = F/x = mg/x = 5 kg * 9.8 m/s^2 / 0.1 m = 49 N/cm. Choice A is incorrect as it is lower than the correct answer. Choices B and D are incorrect as they are higher than the correct answer.

Correct Answer: B

Rationale: The correct answer is B because as a raindrop falls, air resistance increases, counteracting the force of gravity. Initially, gravity pulls the raindrop down, causing it to accelerate. However, as the raindrop gains speed, air resistance becomes stronger, eventually balancing out the gravitational force. This results in a constant velocity rather than acceleration. A: Gravity does pull the raindrop down, but it doesn't do so at a constant rate. The acceleration due to gravity is constant but is countered by air resistance. C: The mass of the raindrop remains constant as it falls, so its mass decreasing is not a factor in its speed. D: Objects in motion do not necessarily decelerate over distance; in the case of the raindrop, air resistance prevents further acceleration.

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.