# Gravity, rotational speed. That kinda stuff.

• 3dsmax

## Homework Statement

It all on the picture provided.

## Homework Equations

F=ma
Fg=6.67e-11((m1m2)/r^2)
Other like basic rotational things not sure if i need them.

## The Attempt at a Solution

All on the pic provided.

(WARNING TO DIAL-UPPERS) this is a link to a really larger version of it. http://i173.photobucket.com/albums/w41/othellodude/bigphysics-1.jpg" [Broken]

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Looks like you have an error in calculation in the first part.
And 10^36 seconds! that is quite some time interval.

I know the time is off. Its weird cause i checked the top calculation 3 times cause it seemed to small. I figured it out now. * goes to see if that fixes every
thing else

<b>EDIT:</b>Dang I am so dumb. I just forgot the e22 at the end of my calculator screen.

Now for the second part I am getting 5.9 E-3 m/s. That can't be right. The world doesn't spin that slow around the sun. Does it?

Now for the second part I am getting 5.9 E-3 m/s. That can't be right. The world doesn't spin that slow around the sun. Does it?

You didn't calculate it quite right. Think centripetal acceleration.

its asking for velocity not acceleration.

And why does every time i post up a question on here no one comes out and tells me how to fix it. They take hours to reply and have me reply back. So i end up having to go to bed before i even figure the darn problem out. I know your trying to help me by not telling me the answers. But i can't learn if i don't even finish the problem which is probably what is going to happen to this problem again. Cause i have to go to bed soon and i doubt someone is going to show me what i did wrong. This is pointless.

Some of us have to sleep too, and work,and...
But to your problem. hage567 gave you a clue. Note that this planet is accelerating, I wonder what that quantity depends upon.

its asking for velocity not acceleration.

And why does every time i post up a question on here no one comes out and tells me how to fix it. They take hours to reply and have me reply back. So i end up having to go to bed before i even figure the darn problem out. I know your trying to help me by not telling me the answers. But i can't learn if i don't even finish the problem which is probably what is going to happen to this problem again. Cause i have to go to bed soon and i doubt someone is going to show me what i did wrong. This is pointless.

Look up what centripetal acceleration is. Did you even do that when I suggested using it? The hints are intended to point you in the right direction, you must take them seriously. If they don't make sense when you first see them, that means you need to go look at your notes and review the material. That's how you will learn to recognize it next time.
If you check your notes, you will see centripetal acceleration is related to velocity. You are dealing with a central force here, so you need to use it.
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