| 1.) S.C. Science Standard:
Investigate and compare the different pitches of sound produced by changing the size, tension, or amount of the vibrating material.
2.) Overview:
Students will explore pitch using a string telephone and straw. Through hands-on exploration students will observe how pitch is changed by an increase or decrease in size or tension. Once the explorations are completed students will be challenged with the concepts learned, using rubber bands and a hardback book. The culminating assessment will be completed on an individual basis.
Teacher Preparation:
Directions to create string telephone. Place a small hole in the bottom of two plastic cups. Take one yard of yarn and place one end of the yarn through the bottom of one cup and the other end of the yarn through the bottom of the other cup. Tie a paper clip on the end of each piece of yarn while in the cup. This will keep the yarn from coming out of the cup.
3.) Focus/Essential Question(s): When the length of an object is increased or decreased what happens to the pitch that is produced? What happens with pitch as tension is increased? Does an object produce a high or a low pitch when the least amount of tension is applied to it?
4.) Time Frame:
Two Forty-Five Minute Class Periods (optional)
5.) Resource/ Materials:
* Plastic clear cups
* Yarn
* Paper clips
* Straw
* Scissors
* Variety of rubber bands
* Hard back book
6.) Culminating Assessment: During the culminating assessment students will work independently to complete the Pitch Assessment Sheet. The teacher will use the scoring guide/rubric provided to score student work.
|
Scoring Guide/Rubric |
| Item One |
1 point |
Student Selected Picture B |
| Item One |
2 points |
Student discussed that string telephone B has more tension or is tighter than A |
| Item Two |
1 point |
Student Selected Picture A |
| Item Two |
2 points |
Discussed that A is longer than B or B is shorter than A
|
Name: _________________________________ Date:
__________________
1. Which string telephone will produce the highest pitch and why?
2. Which straw will produce the lowest pitch and why?
7.) Instructional Activities:
Activity One:
Students will work in groups of two. Each group will be given a string telephone to explore. Students will be directed to place the cup over their ear as their partner plucks on the string. The groups should increase and reduce the amount of tension as they pluck on the yarn and discuss their findings. This first exploration should occur for about ten minutes.
Once each group has finished the exploration the teacher should discuss the term pitch. Pitch is how high or low a sound is. The teacher may demonstrate a high or low sound with any instrument that has been borrowed from the music teacher.
Next the teacher should ask the student to compare the pitch they heard when the yarn has the least amount of tension compared to when they applied the greatest amount of tension.
Students should respond with low pitches were heard when the least amount of tension was applied and high pitches were heard when the greatest amount of tension was applied.
Materials should be collected before beginning activity two.
Activity Two:
In activity one, students explored tension. In activity two, students will explore how the size of an object changes its pitch. Students should use prior knowledge from activity one to distinguish between high and low pitches. Each student will be given a plastic straw and a pair of scissors. Students should chew one inch of the end of the straw to cause it to be flat. Using their back teeth to chew usually works better. When the end is flat, students should blow through the straw to create a sound. Once the students have created a sound the teacher should go around the room one at a time to allow each student to produce their sound. Next students should be directed to blow in the straw, listen to the pitch and then cut off 1/2 inch of their straw and blow again to listen to the pitch. Students should continue to blow, listen and cut 1/2 of the straw until it is approximately 3 inches long.
Warn students to be very careful as they cut. Also pieces of straw will be all over the floor but science can be messy and clean up will occur at the end of this activity.
Once all students have completed this process, the teacher will allow students to discuss with one another what happened to the pitch as the straw became shorter and shorter. Students should be encouraged to share with their peers if their results are the same or different.
To assist students in revising or confirming their results, the teacher should model the blow, listen and cut process. As the straw becomes shorter the teacher should have the students to describe what is occurring with the pitch.
Students should respond with statements such as, as the straw becomes shorter the pitch becomes higher.
To again have students confirm or revise their conclusion regarding how size effects pitches they should be given another straw to complete trail two of this process.
Extension: Students should be given a variety of rubber bands (many sizes and thickness) to place around a hardback book. Students should be challenged to place around the book in order from the highest pitch to lowest pitch without plucking. Once they have done so they should pluck to revise or confirm their prediction and correct as needed.
|
