As we debate the carbon flame war, we know we are riding on a planet that is spinning as it orbits through space around our sun. But how fast?
The Earth's circumference at the Equator is 40,000 kilometers (24,854 mi) and it takes 24 hours to complete one rotation. Therefore, the Earth's speed at the Equator is
D / T = 40,000 km / 24 hr = 1670 km/hr, or 24,854 mi / 24 hr = 1036 mph
Keep in mind that if you move north or south of the Equator, the eastwest parallel of constant latitude narrows. In other words, the distance travelled in a day is less and, of course, the speed is less. You calculate the speed adjustment of rotation using the cosine of your latitude.
For example, at latitude 40 degrees north, you spin in 24 hours:
cos(40) * 1670 km/hr is 1280 km/hr
cos(40) * 1036 mph is 794 mph
So unless you are a penguin, you're spinning rather briskly
Our orbital speed is even faster,
Radius of the Earth's Orbit is 1 AU or 150,000,000 km (93,205,678 mi) Circumference of this orbit is 2 * pi * R or 942,000,000 km, or 585,628,547 mi
It takes 365.2422 days, or 8766 hr
D / T = 942,000,000 km / 8766 hr is 107,000 km/hr or 30 km/sec or 585,628,547 mi / 8766 hr is 66,806 mph or 18.5 mi/sec
So we're rotating and revolving like crazy, but who takes notice?
: )
