Nokea
Which force opposes the relative motion between surfaces in contact?
- A. Tension force
- B. Frictional force
- C. Gravitational force
- D. Magnetic force
Correct Answer: B
Rationale: The correct answer is B: Frictional force. Frictional force opposes the relative motion between surfaces in contact. When two surfaces are in contact and one tries to slide over the other, the frictional force resists this motion, making it harder for the surfaces to move relative to each other. Choice A, tension force, is incorrect because tension force is a force transmitted through a string, rope, cable, or wire when it is pulled tight by forces acting from opposite ends. Choice C, gravitational force, is incorrect as it is the force of attraction between two masses. Choice D, magnetic force, is incorrect as it is the force exerted between magnetic objects.
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What is the formula to calculate kinetic energy?
- A. Kinetic Energy = Mass Velocity
- B. Kinetic Energy = Force Distance
- C. Kinetic Energy = Power Time
- D. Kinetic Energy = Potential Energy · Time
Correct Answer: A
Rationale: Kinetic energy is the energy an object possesses due to its motion. The formula to calculate kinetic energy is KE = 0.5 mass velocity^2, which can also be written as KE = mass (velocity)^2. Therefore, the correct formula is Kinetic Energy = Mass Velocity. Choice B is incorrect because it represents the work formula. Choice C is incorrect as it represents the formula for work done. Choice D is incorrect as it does not accurately represent the formula for calculating kinetic energy.
Which neurotransmitter is associated with mood, sleep, and memory?
- A. Dopamine
- B. Serotonin
- C. Acetylcholine
- D. Glutamate
Correct Answer: B
Rationale: Serotonin is a neurotransmitter that is associated with regulating mood, sleep, and memory. It plays a crucial role in maintaining emotional balance and is often a target in treating mood disorders like depression and anxiety. Serotonin also helps regulate sleep patterns and is connected to memory function. Dopamine (choice A) is more commonly linked to reward, motivation, and movement. Acetylcholine (choice C) is involved in muscle control and memory. Glutamate (choice D) is a major excitatory neurotransmitter in the brain but is not primarily associated with mood, sleep, and memory.
As a car accelerates from rest, what happens to its kinetic energy and the work done on it?
- A. Both kinetic energy and work done increase.
- B. Kinetic energy increases, but work done remains constant.
- C. Work done increases, but kinetic energy remains constant.
- D. Both kinetic energy and work done remain constant.
Correct Answer: A
Rationale: When a car accelerates from rest, its speed and kinetic energy increase. The work done on the car is what increases its kinetic energy, so both kinetic energy and work done increase simultaneously. Option A is correct because acceleration results in an increase in both kinetic energy and the work done on the car. Option B is incorrect because work done is required to increase kinetic energy during acceleration. Option C is incorrect as work done is directly related to the change in kinetic energy. Option D is incorrect as both kinetic energy and work done increase when the car accelerates.
Which of the following is NOT a symptom of asthma, a chronic respiratory condition?
- A. Wheezing
- B. Difficulty breathing
- C. Chest tightness
- D. Fever
Correct Answer: D
Rationale: The correct answer is 'Fever.' Fever is not a symptom commonly associated with asthma. Asthma symptoms typically include wheezing, difficulty breathing, and chest tightness due to inflammation and narrowing of the airways. Fever is more commonly seen in conditions such as infections or inflammatory diseases rather than asthma. Choices A, B, and C are common symptoms of asthma and are related to the constriction and inflammation of the airways, leading to breathing difficulties and chest discomfort.
Which of the following is NOT a greenhouse gas?
- A. Carbon Dioxide
- B. Methane
- C. Oxygen
- D. Water Vapor
Correct Answer: C
Rationale: A) Carbon Dioxide: Carbon dioxide is a greenhouse gas released into the atmosphere through various human activities such as burning fossil fuels and deforestation. It contributes to global warming by trapping heat in the atmosphere. B) Methane: Methane is another greenhouse gas released from sources like livestock, landfills, and natural gas production. It is more potent than carbon dioxide in trapping heat. C) Oxygen: Oxygen is not considered a greenhouse gas. It is a vital component of the Earth's atmosphere necessary for respiration and combustion, but it does not trap heat like greenhouse gases do. D) Water Vapor: Water vapor is a significant greenhouse gas that plays a crucial role in the Earth's climate system by trapping heat in the atmosphere. It is the most abundant greenhouse gas. Therefore, the correct answer is C) Oxygen, as it is not a greenhouse gas.