# Homework Help: Astronaut traveling what effects would she feel?

1. Dec 2, 2008

### goWlfpack

astronaut traveling.. what effects would she feel??

1. The problem statement, all variables and given/known data
An astronaut is traveling in a rocket in outer space in a straight line at a constant speed of 0.5c. Which of the following effects would she experience?

Her heart rate would change.
She would feel heavier.
She would find it harder to breathe.
Some of her dimensions would be shorter.
None of these effects would occur.

2. Relevant equations

3. The attempt at a solution
i thought all of them (except the last would occur) i know that she would feel heavier and i know that it would be harder to breath. im pretty sure the heart rate would change because of the speed, and the dimensions would be shorter because she is traveling so fast right?? or would her dimensions be the same b/c her frame of reference is moving that fast too??

2. Dec 2, 2008

### CompuChip

Re: astronaut traveling.. what effects would she feel??

In special relativity, what clocks and rules are affected by time dilatation and length contraction, respectively?

3. Dec 2, 2008

### goWlfpack

Re: astronaut traveling.. what effects would she feel??

well with length contraction, if the observer is moving, objects appear shorter if they are stationary, and a time interval to an observer in motion will appear longer then an observer at rest. So the heart rate would seem slower?? but would it actually change?

4. Dec 2, 2008

### CompuChip

Re: astronaut traveling.. what effects would she feel??

Well, the point is, that time intervals of one observer A will appear longer for another observer B (in relative motion) but not for A himself. Similarly for length contraction.

So, for example, would she have to had taken length contraction into account while building the bed on board her spaceship before departure?

5. Dec 2, 2008

### goWlfpack

Re: astronaut traveling.. what effects would she feel??

oh ok, so b/c in this case the observer is moving the time intervals will not seem any different? so heart rate stays the same. The dimensions should as well then, b/c the area she is in is moving at the same speed as her.
she would feel heavier though and find it harder to breathe b/c of the pressure and the force of gravity working against her right?

6. Dec 2, 2008

### CompuChip

Re: astronaut traveling.. what effects would she feel??

Do you find it hard to breathe while travelling at 30 km/s through space?