I'm not sure what's the correct answer:
9)Which of these characteristics can only be attributed to a wave of red light?
A)The energy of the wave travels in the same direction as the wave travels.
B)The wave travels by vibrating the particles of the medium at a high rate.
C)The wave travels by compressing and expanding the medium it travels through.
D)The energy of the wave moves perpendicular to the direction the wave travels.
Ans: D
11) In which medium would sound travel the fastest?
A)across a room
B)in a swimming pool
C)through outer space
D)through a railroad track
Ans: A
12) Why do electromagnetic waves not require a medium for travel?
A) because electromagnetic waves travel too fast for stationary particles to move with them
B) because electromagnetic waves transmit energy without compressing the particles of the medium
C) because electromagnetic waves generate their own particles for compression and use these for movement
D) because electromagnetic waves move in two-dimensional space, the particles of mediums exist in 3-D space
Ans:
B
B
To determine the correct answers to these questions, let's analyze each option.
For question 9, we need to determine which characteristic can only be attributed to a wave of red light. Option A states that the energy of the wave travels in the same direction as the wave travels. This is true for all waves, not just red light waves. Option B states that the wave travels by vibrating the particles of the medium at a high rate. This is true for mechanical waves, but not for electromagnetic waves like light. Option C states that the wave travels by compressing and expanding the medium it travels through. This is true for sound waves, but not for light waves. Option D states that the energy of the wave moves perpendicular to the direction the wave travels. This is true for light waves, as they are transverse waves.
Therefore, the correct answer is D.
For question 11, we need to determine in which medium sound would travel the fastest. Option A states across a room, option B states in a swimming pool, option C states through outer space, and option D states through a railroad track. Sound waves travel fastest in solids, due to the closer proximity of particles. In air (such as in a room or swimming pool) and in outer space, sound waves would travel slower. Therefore, the correct answer is A.
For question 12, we need to understand why electromagnetic waves do not require a medium for travel. Option A suggests that electromagnetic waves travel too fast for stationary particles to move with them. While electromagnetic waves do travel at the speed of light, this is not the reason they don't require a medium. Option B states that electromagnetic waves transmit energy without compressing the particles of the medium. This is correct, as electromagnetic waves can travel through a vacuum where there are no particles to compress. Option C suggests that electromagnetic waves generate their own particles for compression and use these for movement, which is not the case. Option D suggests that electromagnetic waves move in two-dimensional space, and the particles of mediums exist in 3-D space, which is not relevant to their requirement for a medium.
Therefore, the correct answer is B.
wrong, wrong, B.
the first two, look at a, b.