# Homework Help: How would I calculate the g's felt?

1. Mar 16, 2004

### SsUeSbIaEs

How would I calculate the g's felt? I thought it was centripetal acceleration divided by gravitational acceleration, then you add 1, is this right at all??

2. Mar 17, 2004

### krab

Why do you want to add 1?

3. Mar 17, 2004

### SsUeSbIaEs

I don't know I saw it on another website I didn't understand it, that's kinda why I am asking on the forum to see if it was right??

4. Mar 17, 2004

### krab

Depends on what you are after. If you want lateral, or horizontal g's from sideways acceleration, then it is just centripetal acceleration divided by g. The number of g's you feel with no acceleration is 1, straight down, but I'm guessing that's not what you are after. On the slight chance that you want to know the resultant number of g's due to a horizontal acceleration and vertical weight, it is given by Pythagorus: Square root of (1 plus the square of (the centripetal acceleration divided by g)).

5. Mar 17, 2004

### SsUeSbIaEs

I had a question on my HW, but my professor has yet to go over g's and the text book I have has absolutely nothing about them neither. The question asks:

You want to design a large, permanent space
station so that no arti¯cial gravity is neces-
sary. You decide to shape it like a large coffee
central axis.
The acceleration of gravity is 9:8 m=s2 :
What rotational speed would be required to
***
I know I how to do the previous part but I have not clue as the how to do the second part.
***
If an astronaut jogged in the direction of the
rotation at 3:9 m=s, how many g's would he
feel?

6. Mar 17, 2004

### Staff: Mentor

In the first part you were given the acceleration and had to find the speed. This second problem is the reverse: Given the speed of the jogger, find the acceleration. krab told how to do it: find the centripetal acceleration and divide by g.

Realize that you are given the speed of the jogger relative to the space station. Don't forget to add in the speed of the space station itself, which you determined in part one. (Also: angular speed X radius = linear speed.)

7. Mar 17, 2004

### SsUeSbIaEs

Thanks, that helps A LOT!!!!