Happy 71st Year-Old Birthday!
Invented by Richard James by accident, the Slinky was introduced to America's adults and kids in 1945. Since that time, 300 million of them have been sold, using enough wire to circle around the Earth's equator 126 times.
For further Information: The Poof-Slinky web site provides some interesting history of the Slinky, the Official Slinky homepage illustrates some scientific uses of a Slinky, and a Robin Whittle's web site shows videos of the world's longest Slinky in action.
Question 1: How much wire is used for each Slinky?
Extension 1: Do you think your answer to the previous question refers to the total length of wire used for a single Slinky...or does it refer to the length of a Slinky when it is coiled up like a torsion spring? Explain.
Extension 2: Let us assume that your calculated length represents the length of a coiled Slinky, which has a diameter of about 2.75 inches. Uncoiled, how long would you expect a Slinky to be [Note: Correct answer is on the About site....plus, if each Slinky was uncoiled into a length of straight wire, how many times would 300 million of them circle around the Earth's equator?
Trivia Question: What does the word Slinky mean? Hint: it is a Swedish word?