how do a scalar quantity and a vector quantity differ

HESI A2

HESI Exams Quizlet Physics

1. How do a scalar quantity and a vector quantity differ?

A. A scalar quantity has both magnitude and direction, and a vector does not.
B. A scalar quantity has direction only, and a vector has only magnitude.
C. A vector has both magnitude and direction, and a scalar quantity has only magnitude.
D. A vector has only direction, and a scalar quantity has only magnitude.

Correct answer: C

Rationale: The correct answer is C. The main difference between a scalar quantity and a vector quantity lies in the presence of direction. A vector quantity has both magnitude and direction, while a scalar quantity has magnitude only, without any specified direction. Examples of scalar quantities include distance, speed, temperature, and energy, whereas examples of vector quantities include displacement, velocity, force, and acceleration. Choices A, B, and D are incorrect because they incorrectly describe the characteristics of scalar and vector quantities.

2. What is 15% of 95?

A. 14.25
B. 18.5
C. 24.25
D. 28.5

Correct answer: A

Rationale: To find 15% of 95, you multiply 95 by 0.15 (which represents 15% as a decimal). Therefore, 95 * 0.15 = 14.25. The correct answer is A. Choice B, 18.5, is incorrect as it does not represent 15% of 95. Choices C and D, 24.25 and 28.5, are also incorrect calculations for 15% of 95.

3. Which of the following is not listed as a detail in the passage about microbes?

A. Babies are born coated with germs from the birth canal.
B. Mice and humans respond to microbes differently.
C. Few people share the same microbes in the same quantities.
D. Human bodies contain far more microbes than they do cells.

Correct answer: B

Rationale: The correct answer is B because the passage does not detail that mice and humans respond to microbes differently. The passage discusses how laboratory mice required a particular strain of bacteria to help their immune systems function correctly, indicating a difference in how mice and humans respond to microbes. Choices A, C, and D are all details mentioned in the passage: A discusses babies being coated with germs from the birth canal, C talks about the variation in microbes among individuals, and D states that human bodies contain more microbes than cells.

4. Which of the following is the weakest intermolecular force?

A. Dipole interactions
B. Hydrogen bonding
C. Van der Waals forces
D. Dispersion forces

Correct answer: D

Rationale: Dispersion forces, also known as London dispersion forces, are the weakest intermolecular forces. They are temporary attractive forces that occur due to momentary shifts in electron distribution within molecules. While dipole interactions, hydrogen bonding, and Van der Waals forces are stronger intermolecular forces, dispersion forces are the weakest because they arise from short-lived fluctuations in electron density. Dipole interactions involve permanent dipoles in molecules, making them stronger than dispersion forces. Hydrogen bonding is stronger than dipole interactions and involves hydrogen atoms bonded to highly electronegative atoms. Van der Waals forces encompass dipole-dipole interactions and dispersion forces, making them stronger than dispersion forces alone.

5. Which muscle is responsible for the extension of the elbow?

A. Biceps brachii
B. Triceps brachii
C. Deltoid
D. Pectoralis major

Correct answer: B

Rationale: The correct answer is B: Triceps brachii. The triceps brachii muscle is responsible for extending the elbow joint. It is located on the back of the upper arm and acts in opposition to the biceps brachii, which is responsible for elbow flexion. The deltoid muscle is primarily responsible for shoulder abduction, not elbow extension. The pectoralis major muscle is involved in movements of the shoulder joint, not the elbow.