in open channel flow a critical property is the free surface which refers to the

HESI A2

HESI A2 Physics Practice Test

1. In open-channel flow, a critical property is the free surface, which refers to the:

A. Interface between the liquid and the container walls
B. Interface between the liquid and a surrounding gas
C. Bottom of the channel
D. Region of highest velocity within the liquid

Correct answer: B

Rationale: The free surface in open-channel flow refers to the interface between the liquid and the surrounding gas, typically the atmosphere. This interface is critical as it determines the boundary between the liquid flow and the open environment. Option A is incorrect as it refers to the liquid-container wall interface, not the free surface. Option C is incorrect because it represents the bottom of the channel, not the free surface. Option D is incorrect as it describes the region of highest velocity within the liquid, not the free surface. Therefore, the correct choice is B.

2. What are saturated fats saturated with?

A. Hydrogen atoms
B. Carbon atoms
C. Oxygen atoms
D. Nitrogen atoms

Correct answer: A

Rationale: Saturated fats are saturated with hydrogen atoms. This means that each carbon atom in the fatty acid chains forming saturated fats is bonded to as many hydrogen atoms as possible. This saturation results in the fatty acid chains being straight and closely packed together, making saturated fats solid at room temperature. Choice B (Carbon atoms), C (Oxygen atoms), and D (Nitrogen atoms) are incorrect because saturated fats are specifically saturated with hydrogen atoms, not carbon, oxygen, or nitrogen atoms.

3. What does the parathyroid hormone regulate?

A. Magnesium
B. Calcium
C. Calcitonin
D. Glucocorticoids

Correct answer: B

Rationale: The parathyroid hormone primarily regulates calcium levels in the blood. It acts to increase calcium levels by stimulating the release of calcium from bones, enhancing calcium reabsorption in the kidneys, and promoting the conversion of vitamin D to its active form, which aids in calcium absorption from the intestines. Therefore, the correct answer is B. Choices A, C, and D are incorrect because the parathyroid hormone does not play a significant role in the regulation of magnesium (Choice A), calcitonin (Choice C), or glucocorticoids (Choice D).

4. Identify the dependent clause in this sentence: The mother dog left her bed as soon as the puppies were asleep.

A. As soon as the puppies were asleep
B. Left her bed as soon as
C. The puppies were asleep
D. The mother dog left her bed

Correct answer: A

Rationale: The correct answer is A: 'As soon as the puppies were asleep' is the dependent clause in the sentence. It functions as an adverbial clause, indicating a time relationship with the action of the mother dog leaving her bed. Dependent clauses rely on independent clauses to form complete sentences and cannot stand alone. Choice B is incorrect because it separates the dependent clause. Choice C is incorrect as it is a noun phrase. Choice D is incorrect as it is an independent clause.

5. What is 60% of 150?

A. 80
B. 90
C. 120
D. 80

Correct answer: B

Rationale: To find 60% of 150, you multiply 0.6 by 150, which equals 90. Therefore, the correct answer is 90. Choice A (80) is incorrect because it does not represent 60% of 150. Choice C (120) is incorrect as it exceeds 100% of 150. Choice D (80) is a duplicate of choice A and does not accurately represent 60% of 150.