Question

Calculate the earth's average speed relative to the sun.

Answer 1

a).  The Earth travels around the sun in a path that's nearly a circle, with a radius of roughly 93 million miles.

The circumference of the circle is (2 · π · radius) = about  5.843 x 10⁸  miles.

Average Speed = (distance covered) / (time to cover the distance)

The time to cover the distance is 1 year.

Speed = (5.843 x 10⁸ mile/year) (year / 365 day) (day / 24 hour)

Speed = (5.843 x 10⁸ / 365·24) (mile · year · day / year · day · hour)

Average speed = 66,705 miles/hour .

b). The Earth's average velocity over a period of 1 year is zero.

Velocity = (displacement) / (time)

Displacement = (distance and direction between start-point and end-point). After one year, the Earth is located at the point where it started, so its displacement over the period of 1 year is zero.