Nokea
What property of matter explains why ice floats on water?
- A. Viscosity
- B. Density
- C. Buoyancy
- D. Surface tension
Correct Answer: C
Rationale: The correct answer is C, buoyancy. Ice floats on water due to buoyancy, a property of matter. When water freezes into ice, it becomes less dense than liquid water, causing it to float. This phenomenon occurs because the molecules in ice are more spread out compared to liquid water, resulting in ice being less dense and able to float on the surface.
Choice A, viscosity, is incorrect because viscosity refers to a fluid's resistance to flow, not its ability to float.
Choice B, density, is incorrect because while ice being less dense than water is the reason it floats, this choice does not explain the specific property that causes this phenomenon.
Choice D, surface tension, is incorrect as it pertains to the cohesive forces between molecules at the surface of a liquid, not the reason why ice floats on water.
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What is the tough, fibrous connective tissue that attaches muscle to bone?
- A. Fascia
- B. Perimysium
- C. Tendon
- D. Ligament
Correct Answer: C
Rationale: Tendons are the correct answer as they are the tough, fibrous connective tissues that attach muscle to bone. They play a crucial role in transmitting the forces generated by muscle contraction to the bones, facilitating movement. Fascia surrounds muscles and provides support, perimysium is the connective tissue sheath around muscle fibers, and ligaments connect bone to bone, stabilizing joints, which makes them distinct from tendons.
Why is the simple columnar epithelium lining the small intestine crucial?
- A. Movement
- B. Support
- C. Absorption
- D. Insulation
Correct Answer: C
Rationale: The simple columnar epithelium lining the small intestine is crucial for absorption. This type of epithelium is specialized for absorption due to its tall and closely packed cells, which increase the surface area available for nutrient absorption. The primary function of the small intestine is to absorb nutrients from digested food, and the simple columnar epithelium's structure aids in this process by providing a large surface area for absorption. Choices A, B, and D are incorrect because movement, support, and insulation are not primary functions associated with the simple columnar epithelium in the small intestine. While these functions are essential in other tissues or organs, absorption is the key role of the simple columnar epithelium in the small intestine.
Which of the following nutrients is essential for muscle growth and repair?
- A. Vitamin C
- B. Protein
- C. Carbohydrates
- D. Fat
Correct Answer: B
Rationale: Protein is essential for muscle growth and repair as it provides the necessary building blocks (amino acids) for muscle tissue synthesis and repair. While vitamins and minerals are crucial for overall health, protein has a specific role in muscle development. Carbohydrates supply energy for workouts, and fats are important for general health but are less directly involved in muscle growth and repair compared to protein.
What happens to the acceleration of an object when the force acting on it is increased, assuming the mass remains constant?
- A. Acceleration increases
- B. Acceleration decreases
- C. Acceleration remains constant
- D. Acceleration becomes zero
Correct Answer: A
Rationale: According to Newton's second law of motion, acceleration is directly proportional to the force acting on an object when the mass is constant. Therefore, if the force acting on an object is increased while the mass remains constant, the acceleration of the object will also increase. This relationship is described by the formula F = ma, where F is the force applied, m is the mass of the object, and a is the acceleration. When force increases, acceleration increases, and vice versa, as long as the mass stays the same. Choice B (Acceleration decreases) is incorrect because acceleration and force have a direct relationship. Choice C (Acceleration remains constant) is incorrect because acceleration changes in response to changes in force. Choice D (Acceleration becomes zero) is incorrect because increasing force does not make acceleration zero; it actually increases it.
A satellite orbits the Earth at a constant speed. Which force is responsible for its circular motion?
- A. Gravitational force from the Earth
- B. Thrust from the satellite's engine
- C. Friction between the satellite and the atmosphere
- D. Normal force from the Earth's surface
Correct Answer: A
Rationale: The gravitational force from the Earth is responsible for keeping the satellite in its circular orbit. This force provides the necessary centripetal force required to maintain the circular motion of the satellite. The gravitational force acts as the centripetal force, pulling the satellite towards the center of the Earth, thereby keeping it in its circular path. Choices B, C, and D do not provide the necessary force to keep the satellite in its circular path. Thrust from the satellite's engine would change the speed or direction of the satellite, not maintain its circular path. Friction between the satellite and the atmosphere would act as a resistive force, slowing down the satellite rather than maintaining its orbit. The normal force from the Earth's surface is perpendicular to the surface and does not contribute to the circular motion of the satellite. Therefore, the correct answer is A, as the gravitational force acts as the centripetal force to keep the satellite in its circular path around the Earth.