Sound Unit

A student set up the investigation below to determine how the thickness of a string affects the vibration of the string when it is plucked. In his investigation, he kept the tightness and length of the strings the same.

What is the most likely result of his investigation?

• A. The thick string would make a louder sound.

• B. The thin string would make a louder sound.

• C. The thick string would vibrate faster.

• D. The thin string would vibrate faster.

A group of students wanted to design a device that could communicate over a distance using sound. They knew that the volume of sound decreased as you moved farther away. They decided to build a drum to communicate by using the number of beats as a code.

Which of the following is the best idea for solving the problem of decreased volume at a distance?

• A. Hit the drum with more force to make larger vibrations.

• B. Hit the drum more quickly to make more vibrations.

• C. Tighten the drum to make a higher pitch.

• D. Use a smaller drumstick to make a higher pitch.

Students were asked to design a device that could communicate over a long distance using sound.

What is the first thing they need to do as they plan their project?

• Build a device to solve the problem.

• Test different devices to see if they can solve the problem.

• Identify the problems that need to be solved by the device.

• Determine if your device will solve the problem.

Sally did an investigation to determine how the length affects the frequency of a vibrating string. She used strings with different lengths and measured the number of vibrations made by each string in one second. All other factors were the same with each string. Her hypothesis was that a shorter string would have a higher pitch. Below are the results of her investigation.

*Hz is the unit for the number of vibrations each second

Does the data support her hypothesis?

• Yes, because the longer strings had more vibrations each second.

• No, because the longer strings had fewer vibrations each second.

• Yes, because the shorter strings had more vibrations each second.

• No, because the shorter strings had more vibrations each second.

The diagram below shows four glasses partially filled with water. When the glass is struck with a spoon the air column above the water vibrates.

Which one would most likely make the lowest pitch?

• A

• B

• C

• D

A group of students investigated how changes in the length of a string would affect the sound the string made. Below is a graph of their data.

What is the best claim they could make with this data?

• Longer strings make a higher pitch sound.

• Longer strings make a louder sound.

• Shorter strings make a higher pitch sound.

• Shorter strings make a louder sound.

The two people in the picture are trying to communicate at a distance. The person on the left is using a device to help him communicate. What problem is he most likely trying to solve?

• He is trying to make the pitch of the sound higher.

• He is trying to make the sound louder.

• He is trying to make the distance shorter.

• He is trying to make the sound more distorted.

A student did an investigation to determine how changing the length of a tuning fork would affect the sound it made. He hit each tuning fork shown below with the same amount of force.

How would the sounds made by the tuning forks differ?

• Tuning fork “A” would be louder.

• Tuning fork “B” would be louder.

• Tuning fork “A” would have a higher pitch.

• Tuning fork “B” would have a higher pitch.

A student is asked to determine what variables affect the sound made when a rubber band is plucked as shown below.

What will most likely happen if he uses more force to pluck the rubber band?

• The pitch of the sound will be higher.

• The pitch of the sound will be lower.

• The sound will be louder.

• The sound will be softer.

A student did an investigation to determine how the thickness of a vibrating string affected the sound it made. The strings were identical except for the thickness. She plucked four different strings and measured the frequency of the sound each one made. The frequency is the number of vibrations the string makes each second. Below are the results of her investigation. *Hertz is the unit for frequency

Which string is most likely the thinnest?

• String 1

• String 2

• String 3

• String 4