6. What characteristic of waves is described by the changing pitch of a siren as a fire truck passes by?
10. When inspecting pipelines and bridge foundations using sonar, which property of waves is relied upon for the technology to work?
12. In a vacuum, what property of all electromagnetic waves remains constant?
To answer these questions, we need to understand the concepts related to waves.
6. The changing pitch of a siren as a fire truck passes by is due to the Doppler effect. The Doppler effect is the change in frequency or pitch of a wave observed by an observer when there is a relative motion between the source of the wave and the observer. In this case, as the fire truck approaches, the sound waves generated have a higher frequency (higher pitch) compared to when the truck is stationary. As the fire truck moves away, the frequency decreases (lower pitch).
10. When using sonar to inspect pipelines and bridge foundations, the technology relies on the property of waves called reflection. Sonar uses sound waves that travel through a medium (usually water) and bounce off objects, reflecting back to the sonar device. By analyzing the time it takes for the sound waves to bounce back and their intensity, sonar systems can create images or maps of underwater structures or objects.
12. In a vacuum, the property of all electromagnetic waves that remains constant is the speed of light. The speed of light in a vacuum is constant and is approximately equal to 299,792,458 meters per second (or about 300,000 kilometers per second). This is one of the fundamental properties of electromagnetic waves, including all forms of light, radio waves, microwaves, and X-rays. In a vacuum, the speed of light remains consistent regardless of the frequency or wavelength of the electromagnetic wave.