{"product_id":"tuning-fork-blue-steel-640hz","title":"Tuning Fork Blue Steel 640Hz","description":"\u003ch2\u003e640Hz, in blue steel, for $7.50\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eSingle blue steel tuning fork, 640Hz. Sold individually.\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003e640Hz sits above middle C and comfortably inside the range where a struck fork rings clearly and long enough to demonstrate with. It is a working laboratory fork rather than a musical tuning reference - the frequency is a round number for calculation, not a note.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat you can do with one fork.\u003c\/strong\u003e Show that sound is vibration by touching a struck fork to water. Show that sound needs a medium. Demonstrate beats against a second fork of a nearby frequency. Measure the speed of sound in air with a resonance tube - 640Hz gives a quarter wavelength of about 13cm at room temperature, which fits a standard tube.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBlue steel\u003c\/strong\u003e is the standard laboratory finish - a heat-treated oxide layer that resists rust without adding mass that would change the frequency.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat the supplier does not publish:\u003c\/strong\u003e the fork's length, its frequency tolerance, and whether a striking block is included. Assume no block. If you need a stated tolerance for quantitative work, ask us and we will get it before you order.\u003c\/p\u003e","brand":"MTA Essentials","offers":[{"title":"Default Title","offer_id":53793078608235,"sku":"EVSER1010408","price":7.5,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0963\/2795\/8891\/files\/ser1010408_tuning-fork-blue-steel-640hz.webp?v=1788358602","url":"https:\/\/megaofficesupplies.com.au\/products\/tuning-fork-blue-steel-640hz","provider":"Mega Office Supplies","version":"1.0","type":"link"}