## Earth’s Velocity

### How fast is the Earth traveling around the Sun?

1 – What do we need to know?  We need to know the total length of the Earth’s path as it orbits the Sun.  We also need to know the time that it takes to make one complete orbit.  Speed is stated as a distance over time.  Like “miles per hour” or “feet per second”.

2 – To calculate the Circumference of the Earth’s orbit we will use the formula for the Circumference of a circle:  C = 2piR     We know that pi=3.14, and we know what 2 equals, so let’s find out what R (Radius) equals. The Radius of the Earth’s orbit is the sum of the radius of the Sun (A = 430,000 miles) and how far the Earth is from the Sun (B = 93,000,000 miles).

So the Radius (A+B) equals 93,430,000 miles.

The orbit of the Earth = C = 2pR = 2 x 3.14 x 93,430,000 miles = 586,740,000 miles.

We’re going to round that number off to 587,000,000 miles, so
C = 587,000,000 miles.

It takes the Earth 365.25 days to orbit the Sun.  Since we usually think of speed (or velocity) in terms of “miles per hour” or “kilometers per hour”, we will need to find out how many hours there are in 365.25 days.

365.25 days / year x 24 hours / day = 8,766 hours in 1 year.

We know the distance (587,000,000 miles) and we know the time it takes (8,766 hours).

If we divide the distance in miles by the time in hours we come up with the “miles per hour”.

587,000,000 miles / 8,766 hours = 67,000 miles per hour.

To summarize our calculations:  The Earth is traveling around the sun at 67,000 miles per hour.