physics
posted by ajo .
The earth moves around the sun in a nearly circular orbit of radius 1.50*10^11m. During the three summer months (an elapsed time of 7.89*10^6s), the earth moves onefourth of the distance around the sun. (a)what is the average speed of the earth? (b) what is the magnitude of the average velocity of the earth during this period?
I can't get the right answer for this problem again.Please give me some hints to do it.Thanks a lot.

What is the circumference of a circle? Divide that by 4, and you have the distance Mother Earth moved. You are given the time,
avg velocity= distance/time.
I get about2.99E4 m/s