- Cape student sues, accuses school officials of slamming her to ground multiple times (04/28/16)43
- Bob Evans restaurant in Cape Girardeau among chain's 21 closings (04/26/16)9
- Missouri House votes to allow concealed weapons without permits (04/28/16)6
- Two hurt in motorcycle wreck on Interstate 55 (04/25/16)1
- Law firm requests information about Cape's traffic cameras (04/25/16)2
- Local lawmakers split over failed medical marijuana bill; voters may have a say (04/26/16)19
- Police report filed, but no charges in incident at Cape Central (04/29/16)31
- Tanker truck catches fire near Oak Ridge (04/24/16)7
- Local company makes eco-friendly kitty litter that cuts cat-box smell (04/25/16)
- Senator introduces bill for I-57 that would connect Sikeston with Little Rock (04/28/16)4
Hooked on Science: Create sound with aluminum rod
Using an aluminum rod and rosin you can create an ear-piercing sound that will grab your attention along with every dog in the neighborhood.
* 2 feet 1/4 inch aluminum rod
STEP 1: Firmly hold the center of the aluminum rod horizontally using the thumb and forefinger of one hand.
STEP 2: Pinch and release a small amount of crushed rosin with the thumb and forefinger of the other hand.
STEP 3: Gently stroke the aluminum rod from the center to the end of the rod using your rosin coated thumb and forefinger. Repeat and slightly increase the pressure of your stroking hand until you hear a high-pitched tone.
Every material has a set of natural vibrations. When you hold the aluminum rod in the center and stroke it with rosin coated fingers, your fingers slip and stick as they slide along the rod. This causes the rod to start moving with one of its natural frequencies of vibration -- a half-wave tone.
Jason Lindsey is a science outreach educator with Hooked on Science. Check out his website www.hookedonscience.org for webcasts and experiments.