# Homework Help: Rotating Space station

1. Jan 9, 2014

### sclatters

1. The problem statement, all variables and given/known data

2. Relevant equations
a=v2/r

f=mv2/r

3. The attempt at a solution
I have been able to complete this first part of the question by equating 0.7g to v2/r, solving to find v then calculating T by looking at the circumference of the cylinder and using v=d/T.

I'm really struggling with the next part. Do I need to calculate the force on the astronaut himself (using f=mv2/r) and perhaps use this to help with finding the apparent weight?

Thanks.

P.s. If anyone could explain how to make the image smaller, that would be great!

Last edited: Jan 9, 2014
2. Jan 9, 2014

### Staff: Mentor

I think tinypic provides thumbnails (=smaller versions) for their uploads. Alternatively, use a graphics program.

The "apparent weight" is the same as the force acting on the astronaut, and you can use the same formula as in the first part, right. Just keep in mind that the velocity is different.

3. Jan 9, 2014

### sclatters

Ok, so I now have the following apparent weights:

Velocity of astronaut=5m/s
Velocity of rotating space station=(√0.7gr)m/s

For ABC: a=((√0.7gr)+5)/r

For ACB: a=((√0.7gr)-5)/r

Do these sound ok?

4. Jan 9, 2014

### Staff: Mentor

Just vstation=√(0.7gr)
The variables have the proper units, if you add more units it gets wrong.

You can calculate the velocity for the rotating space station, as you know g and r.
There are squares missing.

5. Jan 9, 2014

### sclatters

Thanks, that's my poor inputting!

ABC: a=((√0.7gr)+5)2/r

ACB: a=((√0.7gr)-5)2/r

(To be inputted into a calculator)

I hope these look better!

6. Jan 9, 2014

### Staff: Mentor

That notation is a bit ambiguous in terms of "what does the square root cover", but I guess you mean the right thing.

7. Jan 9, 2014

### sclatters

Sorry I didn't know how to extend the square root, I'll have to learn! Thanks for the help!