Question

A synchronous satellite, which always remains above the same point on a planet's equator, is put in orbit around Neptune so that scientists can study a surface feature. Neptune rotates once every 16.1 h. Use the data of Table 13.2 to find the altitude of the satellite.

Mass of Neptune=1.03*10^26 kg
Radius of Neptune=2.21*10^7m

{(6.67*10^-11)(1.03*10^26)(57960)^2/{4pi^2)}^(1/3)=83615480.89

and then I subtracted that answer from 2.21*10^7=61515480.89

when i insert 61515480.89 as my answer homework site says "Your response is off by a multiple of ten". What am I missing?
Thanks

Answer 1

I agree with orbit radius = 8.361*10^7
I think the radius of Neptune is more like 2.48 * 10^7 meters.
so I get 5.88 * 10^7

Answer 2

I agree, you are off by a factor of 10.

8.3E7-2.2E7=6.2E7

Answer 3

I bet they want the answer to be in the form
5.88 * 10^7 meters,
to the same significant figures as given in your table (of course I also do not agree with their planet radius)

Answer 4

I do not understand this off by a factor of ten. Ana's answer, 61515480.89 = 6.15*10^7 approx., looks fine to me except that I disagree about the planet radius.

Answer 5

I inserted 6.2E7 and i also try to do 62000000 but it says the same thing. How else can I insert my answer?

Answer 6

Try 6.15E7
and try
5.88E7

Answer 7

Three of us have done this independently now (I started with my own planet data) and bob and I agree with you.

Answer 8

I appreciate who ever is helping me out, but again I tried 6.15E7 and 5.88E7 still it isn't working out. I can only insert answer two times after that it wont work.
I don't know what else I can do

Answer 9

Nor do I. However the august text had the radius of the planet wrong (or at least not the same as my data) so it is possible that they have the answer wrong. That is all I can think of.

Answer 10

the mass and radius were given by professor so I just followed that.
maybe you are right.
thanks anyway

Answer 11

ps,
It is two physicists helping you out.

Answer 12

I believe you.

Answer 13

i know this is WAY over due but your equation is off and a figure of 10-3 is unaccounted for. your answer should be 6.15e4

Answer 14

Core', even though your answer is WAY overdue, you still helped me out tremendously. I have been looking for this answer for hours now and you just relieved a lot of stress from me, so thank you for posting this answer!!!

Answer 15

I have solution in pdf but cant upload here. eyehelp @ gmail com (no spaces and remember to put a dot before com)