Space equation help ... (1 Viewer)

copeys

Member
Joined
Nov 16, 2008
Messages
91
Gender
Male
HSC
2009
Hey all,

I am in need of some help in understanding some formulas (hopefully not too late for the HSC lol).

In these formulas:




Just a quick question; the v is reference to velocity and the 0 is rest?

But what I need to know is how you know which one is at rest/moving. Because I know they ask it in reference to the stationary etc, so how are you to know which velocity is which?

Sorry, this is all very noobish stuff :0
 

Fortify

♪웨딩드레스
Joined
Mar 20, 2007
Messages
1,281
Gender
Male
HSC
2009
to, lo, mo are the rest frame.
 

ajay098

Member
Joined
Sep 15, 2007
Messages
95
Gender
Female
HSC
2009
Hey all,

I am in need of some help in understanding some formulas (hopefully not too late for the HSC lol).

In these formulas:




Just a quick question; the v is reference to velocity and the 0 is rest?

But what I need to know is how you know which one is at rest/moving. Because I know they ask it in reference to the stationary etc, so how are you to know which velocity is which?

Sorry, this is all very noobish stuff :0
to, mo, lo, is always rest. it is often wat a scientist or the stationary observer measure it to be.

the other one is the one that is travelling near the speed of light as measure by the astronomer or a clock on the spaceship.

hope it helps!
 

boxhunter91

Member
Joined
Nov 16, 2007
Messages
736
Gender
Male
HSC
2009
to, mo, lo, is always rest. it is often wat a scientist or the stationary observer measure it to be.

the other one is the one that is travelling near the speed of light as measure by the astronomer or a clock on the spaceship.

hope it helps!
No it is the other way round.
 

HailSatan

Member
Joined
Oct 17, 2009
Messages
94
Gender
Undisclosed
HSC
2009
No it is the other way round.
This

In these equations, to, mo and lo are what the person travelling at velocity measures.

Take the length equation for example. As v approaches the speed of light, lv approaches 0. A stationary observer watching someone travelling at high speed would see the contraction of length, whereas the person actually travelling would see no difference. Therefore lo is the traveller and lv is stationary.
 

gabgab

Member
Joined
Mar 9, 2009
Messages
73
Gender
Female
HSC
2009
the way i remember it is obserVer is lv etc.

cuz observer has a V in it. lame, but its how i roll i guess.
 

gabgab

Member
Joined
Mar 9, 2009
Messages
73
Gender
Female
HSC
2009
i looked it up in the text book, and in special science terms,

"to = time taken in the rest frame of reference
= proper time."
"tv = time taken as seen from the frame of reference in relative motion to the rest frame"
 

study-freak

Bored of
Joined
Feb 8, 2008
Messages
1,133
Gender
Male
HSC
2009
the way i remember it is obserVer is lv etc.

cuz observer has a V in it. lame, but its how i roll i guess.
hmm, I wonder how it actually works for you, Observer starts with an O....
lo,to,mo....
 

gabgab

Member
Joined
Mar 9, 2009
Messages
73
Gender
Female
HSC
2009
well,

"person on the thing in motion"

doesnt have a v.

it has 4 o's though.

hahha. its just the way i've always remembered it for some reason.
 

HailSatan

Member
Joined
Oct 17, 2009
Messages
94
Gender
Undisclosed
HSC
2009
Stop looking it up in textbooks and use your heads to figure it out by looking at the equations... If I replaced tv and to with t1 and t2 what would you do then?
 

gabgab

Member
Joined
Mar 9, 2009
Messages
73
Gender
Female
HSC
2009
Stop looking it up in textbooks and use your heads to figure it out by looking at the equations... If I replaced tv and to with t1 and t2 what would you do then?


well now, there's no need to get stroppy...

how would you do it Satan? how would you figure it out?
 

HailSatan

Member
Joined
Oct 17, 2009
Messages
94
Gender
Undisclosed
HSC
2009
well now, there's no need to get stroppy...

how would you do it Satan? how would you figure it out?
Read my earlier post.


Also, I'm not trying to come across as stroppy, I'm just pointing out that people are spouting out what they think without knowing why it's right (or wrong).
 

iMAN2

Member
Joined
Mar 22, 2007
Messages
217
Gender
Male
HSC
N/A
The one's with the 0's are from the perspective of the person who is in the rest frame i.e. in the moving object but appears to them as they are not moving. To them, the person outside their spaceship or whatever they are in is relatively moving. E.g. Person in spaceship which is moving at 0.9c.

The one with the v is from the perspective of the observer outside of the moving frame. E.g. Person on earth viewing spaceship move at 0.9c.

This is if we want to find the length that the observer on earth is viewing.

Remember, beacause it is principle of relativity, if the question asks, what legnth is the earth from the astronaut's perspective then l0 becomes the person on earth and lv becomes the astronaut.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top