Sound: Lesson 50 Sound and Size Expectations: 1. Listen carefully 2. Work hard 3. Be responsible

Review: Sound travels in waves. If a sound wave hits a hard flat surface the sound can bounce back, making an echo. Some animals use echos to find food and help them to move safely. We can sometimes see and feel the vibrations that create sound.

Animal Sounds What sounds do these animals make? Which animals make a high pitched sound? Which animals make a low pitched sound?

Ruler Experiment What do you think will happen to the sound if less ruler is hanging off? What do you predict will happen to the sound if more of the ruler is hanging off the table? (on document camera)

Results Check your prediction: When things get smaller, the pitch goes up or gets higher. When things get bigger, the pitch goes down or gets lower.

Pan Flute Experiment Cut straws in different lengths, then line the straws up from shortest to longest. Tape the straws to a stick or piece of paper. Which end do you think will have the higher pitch? The lower pitch? Why?

Assignment: http://www.sfskids.org/templates/instorchfra me.asp?pageid=3 Click on the different sections of the orchestra under 'Choose a family' on the left. Listen to how the pitch changes as the size of the instrument changes. Explore the website and experiment with different instruments and pitch!

I had fun learning and working with you today! Keep your eyes open, scientist! I will see you next lesson.