what is the kinetic energy of a 500 kg wagon moving at 10 ms

HESI A2

HESI A2 Physics Practice Test

1. What is the kinetic energy of a 500-kg wagon moving at 10 m/s?

A. 50 J
B. 250 J
C. 2.5 × 10^4 J
D. 5.0 × 10^5 J

Correct answer: C

Rationale: The formula for calculating kinetic energy is KE = 0.5 × mass × velocity². Given the mass of the wagon is 500 kg and the velocity is 10 m/s, we can substitute these values into the formula: KE = 0.5 × 500 kg × (10 m/s)² = 0.5 × 500 kg × 100 m²/s² = 25,000 J or 2.5 × 10⁴ J. Therefore, the kinetic energy of the 500-kg wagon moving at 10 m/s is 2.5 × 10⁴ J. Choice A (50 J) is incorrect because it is too low; Choice B (250 J) is incorrect as it does not match the correct calculation; Choice D (5.0 × 10^5 J) is incorrect as it is too high. The correct answer is C (2.5 × 10^4 J).

2. What is the main idea of the passage about MRSA?

A. Methicillin-resistant Staphylococcus aureus (MRSA) is a significant problem both within and outside of hospitals, and there are ways to mitigate the risk.
B. A new textile made of nanomaterials could significantly reduce the spread of hospital-associated MRSA infections.
C. There are multiple strains of MRSA, and they pose various risks beyond just fatality.
D. MRSA is a significant problem both within and outside of hospitals, but there are ways to mitigate the risk.

Correct answer: D

Rationale: The main idea of the passage is that MRSA is a significant issue both within and outside of hospitals. It highlights the challenges posed by MRSA, including its resistance to antibiotics, high mortality rates, and widespread presence in various settings. While the development of new technologies like nanomaterial textiles shows promise in reducing hospital-associated MRSA, the passage also emphasizes the importance of practicing good hygiene to prevent community-associated MRSA infections. Choices A, B, and C are incorrect because they do not capture the comprehensive overview of MRSA provided in the passage. Choice A encompasses the main idea by emphasizing the significance of MRSA and ways to mitigate the risk. Choice B focuses on a specific solution rather than the broader issue of MRSA. Choice C is incorrect as it oversimplifies the risks associated with MRSA strains by only mentioning fatality.

3. Which factor does not affect the reaction rate of a chemical reaction?

A. Temperature
B. Surface area
C. Concentration of reactants
D. Color of the reactants

Correct answer: D

Rationale: The color of reactants is not a factor that affects the rate of a chemical reaction. Temperature, surface area, and concentration of reactants are known factors that influence the reaction rate. Temperature plays a significant role in altering the reaction rate by affecting the kinetic energy of molecules. Surface area impacts the rate by providing more area for collisions to occur. Concentration affects the frequency of effective collisions. On the other hand, the color of reactants is a physical property that does not directly affect the speed of a chemical reaction.

4. How do the intercostal muscles between the ribs assist with respiration?

A. By protecting the delicate bronchioles and alveoli
B. By signaling a decrease in intra-alveolar pressure
C. By enlarging and reducing the space in the thorax
D. By maintaining a medial separation between pleurae

Correct answer: C

Rationale: The intercostal muscles located between the ribs play a crucial role in respiration by aiding in the enlargement and reduction of the space in the thorax. During inspiration, these muscles contract, lifting the rib cage, which increases the volume of the thoracic cavity and allows the lungs to expand and fill with air. This process directly relates to the expansion of the thorax rather than protecting bronchioles and alveoli (Choice A), signaling intra-alveolar pressure changes (Choice B), or maintaining the separation between pleurae (Choice D). Therefore, the correct answer is C.

5. How many different types of tissues are there in the human body?

A. four
B. six
C. eight
D. ten

Correct answer: A

Rationale: There are four major types of tissues in the human body: epithelial, connective, muscle, and nervous tissues. Epithelial tissue covers body surfaces, connective tissue supports and binds other tissues together, muscle tissue enables movement, and nervous tissue allows for communication between different parts of the body. Choices B, C, and D are incorrect because the human body has four main types of tissues, not six, eight, or ten.