Nursing Elites

1. When a person pushes a box across the floor, which of the following forces is NOT doing work?

• A. The person's pushing force
• B. The normal force from the floor
• C. The gravitational force on the box
• D. The frictional force between the box and the floor

Correct answer: B

Rationale: The normal force from the floor is perpendicular to the direction of motion of the box, so it does not contribute to the work being done. Work is only done by forces acting in the direction of motion of an object. In this case, the normal force is acting at a right angle to the motion, hence it does not perform any work on the box. The person's pushing force, the gravitational force, and the frictional force are all acting in the direction of motion of the box, so they contribute to the work being done in moving the box across the floor.

2. What happens to the kinetic energy of an object when its mass is doubled?

• A. Kinetic energy remains the same
• B. Kinetic energy halves
• C. Kinetic energy doubles
• D. Kinetic energy quadruples

Correct answer: A

Rationale: The correct answer is that the kinetic energy remains the same. Kinetic energy is directly proportional to the mass of an object and the square of its velocity. When the mass is doubled, the kinetic energy would increase if the velocity remains constant. However, in this question, only the mass is mentioned, not the velocity. Therefore, when the mass is doubled, the kinetic energy remains the same as long as the velocity remains constant. Choices B, C, and D are incorrect because they incorrectly suggest changes in kinetic energy that do not accurately reflect the relationship between mass and kinetic energy described in the question.

3. How does the mass of an object affect its inertia?

• A. Mass has no impact on inertia
• B. Higher mass increases inertia
• C. Higher mass decreases inertia
• D. Mass influences gravitational force, not inertia

Correct answer: B

Rationale: Inertia is the resistance of an object to changes in its state of motion. The greater the mass of an object, the greater its inertia because it requires more force to change its state of motion. This concept aligns with Newton's first law of motion, which states that an object at rest will remain at rest, and an object in motion will continue in motion with the same speed and direction unless acted upon by an external force. Therefore, higher mass increases inertia, making it more difficult to alter the object's state of motion. Choice A is incorrect as mass does impact inertia. Choice C is incorrect as higher mass actually increases inertia, not decreases it. Choice D is incorrect as while mass does affect gravitational force, it also directly impacts inertia.

4. What is the name of the muscle responsible for pumping blood throughout the body?

• A. Bicep
• B. Tricep
• C. Deltoid
• D. Cardiac muscle

Correct answer: D

Rationale: The correct answer is D, Cardiac muscle. The cardiac muscle is specifically designed to pump blood throughout the body and is found in the heart. In contrast, the bicep, tricep, and deltoid are skeletal muscles responsible for joint movement, not for pumping blood. The bicep is responsible for elbow flexion, the tricep for elbow extension, and the deltoid for shoulder abduction.

5. Which of the following types of immunity is provided by the secretion of antibodies by B-cells?

• A. Cell-mediated
• B. Humoral
• C. Innate immunity
• D. Phagocytic

Correct answer: B

Rationale: The correct answer is B: Humoral. Humoral immunity involves B-cells secreting antibodies to fight pathogens. In this type of immunity, antibodies circulate in the blood and other body fluids to neutralize pathogens and prevent infections. Cell-mediated immunity, on the other hand, involves the activation of T-cells to directly attack infected or abnormal cells, not the secretion of antibodies. Innate immunity refers to the nonspecific defense mechanisms the body has in place from birth, such as physical barriers and inflammatory responses. Phagocytic immunity is not a recognized type of immunity; phagocytosis is a mechanism used by cells like macrophages to engulf and digest pathogens, but it is not a specific form of immunity like humoral or cell-mediated immunity.

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