when a junked car is compacted which statement is true
Logo

Nursing Elites

HESI A2

HESI Exams Quizlet Physics

1. When a junked car is compacted, which statement is true?

Correct answer: C

Rationale: When a junked car is compacted, its volume decreases while its mass remains the same. As a result, the car's density increases because density is mass divided by volume. Choice A is incorrect because the mass of the car remains the same. Choice B is incorrect because the mass does not decrease. Choice D is incorrect because the density increases as the volume decreases, not decreases.

2. A spring has a spring constant of 20 N/m. How much force is needed to compress the spring from 40 cm to 30 cm?

Correct answer: D

Rationale: The change in length of the spring is 40 cm - 30 cm = 10 cm = 0.10 m. The force required to compress or stretch a spring is given by Hooke's Law: F = k × x, where F is the force, k is the spring constant (20 N/m in this case), and x is the change in length (0.10 m). Substituting the values into the formula: F = 20 N/m × 0.10 m = 2 N. Therefore, the correct answer is 2 N. Choice A (200 N) is incorrect because it miscalculates the force. Choice B (80 N) is incorrect as it does not apply Hooke's Law correctly. Choice C (5 N) is incorrect as it underestimates the force required.

3. For the core of an electromagnet, a material with high:

Correct answer: B

Rationale: A material with high permeability is preferred for the core of an electromagnet because it allows magnetic field lines to pass through it easily, enhancing the strength of the magnetic field generated. Choice A is incorrect because high resistivity would impede the flow of current in the coil, reducing the strength of the magnetic field. Choice C is incorrect as permittivity is related to electric fields, not magnetic fields. Choice D is also incorrect because dielectric strength is about insulating materials against breakdown under an electric field, not relevant to enhancing magnetic fields.

4. Which of the following materials has the lowest density?

Correct answer: B

Rationale: Cork has the lowest density among the given options. Cork is a lightweight material derived from the bark of cork oak trees and is known for its low density, making it float on water. Water, aluminum, and steel have higher densities compared to cork. Water is denser than cork because it has a consistent density of 1 g/cm³. Aluminum and steel are metals with much higher densities due to their atomic structures, making them denser than cork.

5. Bernoulli's principle for an incompressible, inviscid fluid in steady flow states that the mechanical energy, consisting of:

Correct answer: C

Rationale: Bernoulli's principle states that the sum of pressure energy (P), kinetic energy per unit volume (½ρv²), and potential energy per unit volume remains constant along a streamline in an incompressible, inviscid fluid. This means the total mechanical energy of the fluid is conserved, making Choice C the correct answer. Choices A, B, and D are incorrect because Bernoulli's principle involves the conservation of the total mechanical energy, not just pressure, velocity, or density alone.

Similar Questions

Sublimation is the change in matter from solid to gas or gas to solid without passing through a liquid phase. Outside of the laboratory, which solid provides the best example of this?
Fluids can be categorized based on their shear stress-strain rate relationship. An ideal fluid exhibits:
A constant force is exerted on a stationary object. In this scenario, work is:
For steady, incompressible flow through a pipe, the mass flow rate (ṁ) is related to the fluid density (ρ), cross-sectional area (A), and average velocity (v) via the continuity equation:
The amount of energy lost in a circuit due to electrical resistance is dissipated in the form of:

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

Other Courses