Sound comes from human-made and natural sources. An example of a human-made source would be a radio. An example of a natural source of sound would be a waterfall. The sound travels to our ears the same if it is human-made or natural.

Vibrations create sounds. When something vibrates, like a rubber band, a sound is produced. The vibrations create sound waves that travel to our ears for processing.

Of all of the examples calling 911 during an emergency and talking to an operator is a way of communicating using sounds and solving a problem. The other choices make a sound, but there is no problem being solved. Many times we need to communicate with people over a distance, so inventions like the telephone help solve this issue.

One of the old-fashioned ways kids would communicate over a distance before there were cell phones and computers was to make their phones! You could attach two paper cups to either end of a string and use them to talk into and listen. The sound is transmitted, and friends could use them to speak across a yard or bedroom. The other options allowed people to communicate over a distance but were not using sound.

The best plan based on the teacher's instructions would be Group 1's plan. They have replaced spoken language with a communication system based on sound. They have an idea of what each sound means and how it will be used. The other group is relying on head shakes and using the drum for celebrating, not communicating.

The best way for Sadie to test her design is to build it and use it. If she makes it and finds some things that need to be fixed or changed, she can work on her design. If she never actually builds it, she won't know if it works.

The object that would be most useful for communicating over a distance would be the whistle. The other objects make noise, but they are quiet and may not be heard depending on how far the teacher separates the students. Reina could make different sounds with the whistle to communicate, so it could be an excellent place to start her device.

This statement is true. The best way to start the design process would be to ask questions about what you need to make, observe other devices already created or designed, and to gather information about needs and how things work.

A handbell would be the best device to choose if you were trying to communicate with other people using sound. A whisper does make a sound, but it will not travel far because it is so soft and quiet. A sign is a great way to share your location, but it does not use sound. A handbell is loud and could easily be heard.

The most important aspect listed for a device trying to communicate sound across a distance would be how loud it is. If the sound is too soft or quiet, no one will hear the message being sent. The "prettiness" of the sound and how heavy it is are not the most important characteristics.