By Patty Rooks on November 2, 2019.
praxis@praxismh.ca@PraxisMedHat I am feeling a little mischievous today so I have a fun but loud experiment to do. What can I say? Here is a chance to make all the noise you want in the name of learning science! This is also a simple activity for those teachers out there that may be on the Hearing and Sound Unit in their classroom. Grab a pair of ear plugs and let’s get started *Remember to ask an adult before doing this experiment. Materials – plastic drinking straw – ruler – marker – scissors Procedure 1. Measure 20 centimetres from one end of the straw. Place a mark here. 2. Draw a notch on each side of the straw. 3. Cut these notches out – they will look a bit like a triangle on each side. 4. From the other end of the straw, measure tee centimetres, place a mark, measure three more centimetres from this mark and put a line here; measure three more centimetres and place another mark here. 5. Using the scissors cut a slit at each of these marks. Please be careful you do not cut yourself, it can be a bit tricky. 6. Place your mouth just above the top of the straw where you cut the triangles. Place your fingers over the holes. 7. BLOW! 8. What do you hear? 9. Try adjusting your fingers over different holes at different times. 10. Does this make a difference? What is going on? You made a musical instrument called an oboe in this experiment. Just like a real oboe, needs in order to work, you made a reed. This is at the top of the straw where you cut out the triangle shapes. Just like a real oboe, the reed opens and closes at a very high speed as you blow into it. This is a bit tricky and may take a bit of practice to get it so you actually hear some sound. The reed also allows the air to flow into the straw and then stop the flow. It is this vibrating air that makes the sound. Did you know that each time you blow into your oboe you can hear a different sound? By moving your fingers over or off of the different holes, you are regulating the length of the air column and this in turn decides the pitch. The shorter the air column, the faster the straw will vibrate and the higher the note. Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. NOTE our NEW address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca. 24