# What will show scale inside rocket?

1. Nov 18, 2013

### Maciej Ma

I want to kindly ask about opinion what will be if :

a) rocket's speed < gravitation
b) rocket's speed > gravitation

************************************************************
Earth ----- Rocket[W]m >>> constant V

[W]- scale can measure kg
[m]- person mass

Scale is showing Qearth + Qrocket

Qearth - gravitation between person and Earth (Newton's grav. force )
Qrocket - gravitation between person and rocket (Newton's grav. force)
*****************************************************

Rocket[W]m >>>>> constant acceleration

Rocket[W]m ----------------> G<V< C

G - gravitation speed in Vacuum , C- light's speed

Scale is showing Af + Qrocket
Af - acceleration forces ( rocket's engine work give constant a )
Qrocket - gravitation between person and rocket ( Newton's gravitation )

Qrocket = 0 WHY ???

Mach- first engineer who described Supersonic Speed problem

( please look on 4 animations below link (left side of page )

V= zero , V>0 , V= sound , V>sound //1,4 Mach

http://www.acs.psu.edu/drussell/Demos/doppler/doppler.html

What will show scale if body m is moving faster than own gravitation ?

Rocket represent mass M
Person represent mass m

M---r----m ----------> G<V

Mass M is sending (EM) waves but waves can not touch the mass m
mass m is going faster than own signals

what will show scale ?

M---r----m ----------> G<V

M---r----m ----------> V <G

More better is showingbproblem below example

P1.........Sun-----------Earth ------> cnstant V

P1...............................................................SUN -----------Earth >>>> constant acceleration

Sun Was in past in Point 1 . Sun started gravitation signal in P1 .

How big Intensity will feel Earth ? Haw far from P1 Earth will register signal that started in P1 ?

please compare 5-6 minutes ----> constant motion situation

to 5-6 minutes >>>>>>>>>>>>>>>>>>>>>>>>>>>>>cnastant acceleration situation

1930 Tolman surface brightness test
http://en.wikipedia.org/wiki/Tolman_surface_brightness_test

Last edited: Nov 18, 2013
2. Nov 18, 2013

### Staff: Mentor

Assuming that nothing on the scale changes, the only thing that will vary the reading of the scale is the acceleration (not the speed!) of the rocket relative to some nearby object in free fall. That will be true in all the cases you describe above, and is the only thing you need to know to analyze them all.

You mention the "speed of gravity" several times. There's no such thing; the gravitational field is already spread through all of space so no matter how far and fast you move, the gravitational field will already be there.

(So far there's no relativity in these problems - it's all classical mechanics)

3. Nov 18, 2013

### Maciej Ma

m1-----r----mass M ----r-------m2 >>>>motion
..................Fire

Fire = that mass is changing temp.

m1 or m2 will feel more faster
that mass M is changing power of own gravitation ?

( distance r = 1 meter or 1000 meters or 150 000 000 km )

how much time need light for distance r = 1m
how much time need light for distance r = 1000 m

how much time need gravitation to inform mass m 1 ,m2 about problem ?

please imagine that m1,m2 are perpendicular to motion >>>

30 km/s ??? .... 220 km/s

Last edited: Nov 18, 2013
4. Nov 18, 2013

### pervect

Staff Emeritus
I see you've got some answers already, but I find it hard to guess what you might even mean by a) and b) above.

Speed we can measure in units of velocity (meters/second for example). I'm not aware of any definition of "gravitation" that has compatible units.

And to compare quantites they must have compatible units.