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. Which of the following is an example of an organ?

• A. Skin
• B. Neuron
• C. Brainstem
• D. DNA

Correct answer: A

Rationale: The correct answer is A, 'Skin.' The skin is the largest organ in the human body and consists of multiple tissue types working together to perform various functions such as protection, sensation, and temperature regulation. Choice B, 'Neuron,' is a specialized cell in the nervous system and not an organ. Choice C, 'Brainstem,' is a part of the central nervous system composed of nerve tissues but is not an organ on its own. Choice D, 'DNA,' is a molecule that carries genetic instructions, not an organ.

3. What type of bond connects amino acids to form proteins?

• A. Covalent
• B. Peptide
• C. Ionic
• D. Hydrogen

Correct answer: B

Rationale: The correct answer is 'Peptide'. Peptide bonds are the specific type of bond that connects amino acids together to form proteins. These bonds form through a condensation reaction between the amino group of one amino acid and the carboxyl group of another amino acid, creating a covalent bond. While covalent bonds are involved in the formation of peptide bonds, the direct bond connecting amino acids in proteins is the peptide bond. Ionic bonds involve the attraction between charged particles, and hydrogen bonds are weaker bonds compared to covalent and peptide bonds, playing a different role in protein structure.

4. What property of a wave remains unchanged when it passes from one medium to another with the same speed?

• A. Frequency
• B. Wavelength
• C. Amplitude
• D. Speed

Correct answer: A

Rationale: When a wave passes from one medium to another with the same speed, its frequency remains unchanged. Frequency is a characteristic of the source of the wave and does not depend on the medium through which the wave is traveling. Wavelength and speed of the wave can change when passing from one medium to another, but frequency remains constant. This is because the frequency of a wave is determined by the source that produces it, and as long as the speed remains constant, the frequency will not be altered. Amplitude, on the other hand, can change based on factors like energy loss or gain, but it is not a property that remains constant when a wave moves between different mediums with the same speed. Speed, although important for the wave's propagation, is not the property that remains unchanged when the wave transitions between mediums with the same speed. Therefore, the correct answer is frequency.

5. When magnesium metal reacts with hydrochloric acid, hydrogen gas is produced. What evidence suggests a chemical reaction is occurring?

• A. A change in color
• B. The formation of a gas
• C. Dissolving in a liquid
• D. No change in temperature

Correct answer: B

Rationale: The formation of a gas is evidence of a chemical reaction occurring. In this case, when magnesium metal reacts with hydrochloric acid, hydrogen gas is produced, indicating a chemical change is taking place. The production of gas is a clear indication of a chemical reaction, as new substances are being formed. A change in color might suggest a physical change, dissolving in a liquid could be a physical or chemical change depending on the context, and no change in temperature does not necessarily indicate a chemical reaction, as some reactions are endothermic or release small amounts of heat that may not be easily noticeable.

Similar Questions