Which of the following best predicts what will happen when white light passes through a green object?
- A. The object will mostly reflect the green part of the light.
- B. The object will mostly absorb the green part of the light.
- C. The object will appear black.
- D. The object will appear white.
Correct Answer & Rationale
Correct Answer: A
When white light passes through a green object, the object primarily reflects green wavelengths while absorbing others. This reflection causes the object to appear green to our eyes. Option B is incorrect because if the object absorbed the green part of the light, it would not appear green. Option C is not valid, as a black appearance would result from the object absorbing all wavelengths of light, not reflecting any. Option D is also wrong; an object appears white when it reflects all wavelengths of light equally, which does not apply to a green object.
When white light passes through a green object, the object primarily reflects green wavelengths while absorbing others. This reflection causes the object to appear green to our eyes. Option B is incorrect because if the object absorbed the green part of the light, it would not appear green. Option C is not valid, as a black appearance would result from the object absorbing all wavelengths of light, not reflecting any. Option D is also wrong; an object appears white when it reflects all wavelengths of light equally, which does not apply to a green object.
Other Related Questions
An astronaut travels to the Moon, where the magnitude of the force of gravity is one-sixth the magnitude of the force of gravity on Earth. On the Moon, which of the following is true?
- A. The astronaut's mass is one-sixth of his mass on Earth.
- B. The astronaut's weight is one-sixth of his weight on Earth.
- C. The astronaut's mass is six times his mass on Earth.
- D. The astronaut's weight is six times his weight on Earth.
Correct Answer & Rationale
Correct Answer: B
An astronaut's mass remains constant regardless of location; therefore, option A is incorrect as mass on the Moon is the same as on Earth. Option C is also incorrect because mass does not change based on gravitational force. Option D misrepresents weight; weight is dependent on gravity, and since the Moon's gravity is one-sixth that of Earth's, the astronaut's weight is one-sixth, not six times. Thus, option B accurately reflects that the astronaut's weight on the Moon is one-sixth of his weight on Earth, aligning with the relationship between weight and gravitational force.
An astronaut's mass remains constant regardless of location; therefore, option A is incorrect as mass on the Moon is the same as on Earth. Option C is also incorrect because mass does not change based on gravitational force. Option D misrepresents weight; weight is dependent on gravity, and since the Moon's gravity is one-sixth that of Earth's, the astronaut's weight is one-sixth, not six times. Thus, option B accurately reflects that the astronaut's weight on the Moon is one-sixth of his weight on Earth, aligning with the relationship between weight and gravitational force.
The speed of light in empty space, that is, a vacuum, is 300,000 km/s. The speed of sound in empty space is:
- B. greater than 0 but less than 300,000 km/s
- C. 300,000 km/s
- D. greater than 300,000 km/s
Correct Answer & Rationale
Correct Answer: A
The speed of sound requires a medium, such as air or water, to propagate; it cannot travel through a vacuum. Therefore, the speed of sound in empty space is effectively zero. Option B suggests that the speed of sound is greater than 0 but less than 300,000 km/s, which is incorrect because sound cannot exist in a vacuum. Option C states it is 300,000 km/s, which misrepresents sound's nature, as this speed is specific to light. Option D claims it is greater than 300,000 km/s, which is impossible since sound cannot travel in a vacuum at all. Thus, the only valid conclusion is that the speed of sound in empty space is zero.
The speed of sound requires a medium, such as air or water, to propagate; it cannot travel through a vacuum. Therefore, the speed of sound in empty space is effectively zero. Option B suggests that the speed of sound is greater than 0 but less than 300,000 km/s, which is incorrect because sound cannot exist in a vacuum. Option C states it is 300,000 km/s, which misrepresents sound's nature, as this speed is specific to light. Option D claims it is greater than 300,000 km/s, which is impossible since sound cannot travel in a vacuum at all. Thus, the only valid conclusion is that the speed of sound in empty space is zero.
Which of the following best explains why an ice skater is able to coast on ice for a long distance without pushing off in a straight line across the ice?
- A. The force of friction on the blades of the skates is greater than the force of friction on the ice.
- B. The force of friction on the blades of the skates is less than the force of friction on the ice.
- C. The ice exerts a constant forward force on the skater.
- D. The buoyant force on the blades of the skates is greater than the weight of the skater.
Correct Answer & Rationale
Correct Answer: B
An ice skater can glide smoothly due to the minimal friction between the skate blades and the ice, which is significantly lower than the friction experienced on other surfaces. This reduced friction allows the skater to maintain momentum over longer distances without needing to push off. Option A is incorrect because it suggests greater friction on the blades, which would hinder movement. Option C is misleading, as the ice does not exert a forward force; instead, the skater continues moving due to existing momentum. Option D is also wrong; while buoyancy affects weight in water, it does not apply to ice skating, where weight and friction are the primary factors.
An ice skater can glide smoothly due to the minimal friction between the skate blades and the ice, which is significantly lower than the friction experienced on other surfaces. This reduced friction allows the skater to maintain momentum over longer distances without needing to push off. Option A is incorrect because it suggests greater friction on the blades, which would hinder movement. Option C is misleading, as the ice does not exert a forward force; instead, the skater continues moving due to existing momentum. Option D is also wrong; while buoyancy affects weight in water, it does not apply to ice skating, where weight and friction are the primary factors.
Which of the following is a statement that proposes a possible explanation for a phenomenon and can be tested through experimentation?
- A. An observation
- B. A variable
- C. An experiment
- D. A hypothesis
Correct Answer & Rationale
Correct Answer: D
A hypothesis is a statement that proposes a possible explanation for a phenomenon and can be tested through experimentation. It serves as a foundation for scientific inquiry. Option A, an observation, refers to data gathered through the senses and does not propose an explanation. Option B, a variable, is a factor that can change in an experiment but does not itself explain phenomena. Option C, an experiment, is a method used to test a hypothesis but is not a statement proposing an explanation. Thus, only a hypothesis encapsulates a testable explanation.
A hypothesis is a statement that proposes a possible explanation for a phenomenon and can be tested through experimentation. It serves as a foundation for scientific inquiry. Option A, an observation, refers to data gathered through the senses and does not propose an explanation. Option B, a variable, is a factor that can change in an experiment but does not itself explain phenomena. Option C, an experiment, is a method used to test a hypothesis but is not a statement proposing an explanation. Thus, only a hypothesis encapsulates a testable explanation.