a ringing alarm clock is put under a glass jar. The air is slowly removed from the space around it. What will happen as the air is removed?

Question

1. the clock will slowly become quieter and will ultimately fade from view
2. the appearance of the clock will not change, but its sound will become fainter.
3. the appearance of the clock and the sound of the clock will not change
4. the clock will slowly become less visible, until you can only hear it

Answer 1

As air is removed from the space around the ringing alarm clock under a glass jar, the sound it produces will become fainter because sound requires a medium (like air) to travel through. As the air is removed, the sound waves will have less medium to travel through, leading to a decrease in the intensity of the sound.

However, the appearance of the clock will not change just because the air is being removed; it will remain visible.

Therefore, the correct answer is:

2. The appearance of the clock will not change, but its sound will become fainter.