Expert: Bobby Soltani - 1/24/2005

Question
The average distance between the sun and the planet Neptune is 4.5 x 10^9 km.  About how far does Uranus travl in orbit around the sun ( assume a circular orbit)

A) 2.8 x 10^10 kn
B) 8.2 x 10^10 kn
C) 1.8 x 10^10 kn
D) 2.8 x 10^-10 km

Answer
Hi,

I think the question must ask, "how far does NEPTUNE travel in orbit around the sun" since we are only given information about Neptune.  From the given information, we know what the radius of the circle traveled by Neptune is 4.5 x 10^9 km.  We want the circumference of the circle to determine how far it traveled.  The equation for the circumference is C = 2*pi*r

C = 2*pi*4.5*10^9
C = 2.8 x 10^10 km

So, the answer is A.

Let me know if you have questions.

Bobby