College Physics Problem 2.5

(a) Calculate Earth’s average speed relative to the Sun.
(b) What is its average velocity over a period of one year?


a) The average speed of the earth is equal to the distance traveled divided by the time.

Average speed of the Earth=frac{Distance traveled}{Total time of travel}

Average speed of the Earth=frac{2 pi r}{t}

Average speed of the Earth=frac{2 pi left (1.50 times10^{11} mright )}{365.25 days} times frac{1 day}{24 hours} times frac{1 hour}{3600 s}

Average speed of the Earth=2.99 times 10^{4} m/s

b) After a period of 1 year, the planet Earth has already returned to its original position with respect to the Sun. This means that we do not have any displacement. Therefore, the average velocity is zero.

v=0 m/s