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? The appearance of the clock will not change, but it sound will become fainter. The clock will slowly become less visible until you can only hear it. The appearance of the clock and the sound of the clock will not change. The clock will become quieter, ultimately fade from view.
The appearance of the clock will not change, but its sound will become fainter as the air is removed from the space around it. The sound of the clock requires air molecules to travel through, so as the air is removed, the sound waves will have less medium to travel through, resulting in a decrease in volume.
