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How Fast are You Spinning?

Our Earth is ALWAYS spinning. Yet, just how fast is earth rotating? Everyone on Earth spins 360 degrees in a 24 hour period. 360 degrees / 24 hrs = 15 degrees per hour. This is Earth's ANGULAR SPEED (amount of rotation per unit time). This remains constant. Yet what's NOT CONSTANT is one's LINEAR SPEED (distance traveled per unit time). In a 24 hour period, we all--(unless we're flying a great distance in an airplane)--"spin along" a circle of latitude. Some circles of latitude are bigger than others. (Observe in the applet below.) Since this is the case, we CANNOT ALL HAVE the same LINEAR SPEED as every other person on the planet! Let's assume Earth to be a perfect sphere (for simplicity's sake!) According to NASA's website (, Earth has a mean radius of 3,958.8 miles. To successfully answer the 2 questions in this applet, all you will need is the following: 1) The latitude of your location 2) A good working knowledge of some basic geometry formulas. 3) A good working knowledge of basic right-triangle trigonometry. Have fun with this! (Don't check a checkbox before answering the question that precedes it!)