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Sep 16, 2018 at 17:30 review Close votes
Sep 22, 2018 at 3:05
Sep 16, 2018 at 17:14 comment added knzhou Possible duplicate of Why is the work done by a rocket engine greater at higher speeds?
Jan 30, 2015 at 15:12 history protected Qmechanic
Mar 23, 2014 at 17:38 answer added Mellester timeline score: 1
Sep 11, 2013 at 11:18 comment added babou The question, presented as a paradox, is very good. There is of course a fallacy, which has to do with proper consideration of momentum conservation. Not all the energy is spent on accelerating the ship (that is the first key), actually it goes mostly to the ejected reaction mass. Nervertheless you are right that it does accelerate each time by the same amount (assuming same reaction mass and negligible mass change), in any inertial frame, which the bicycles will not do. You can try to find out why, or look at this answer.
Sep 9, 2013 at 16:28 answer added babou timeline score: 18
Dec 7, 2012 at 14:16 answer added Bogdan Alexandru timeline score: -2
Nov 23, 2012 at 18:13 comment added kηives @JoseJavierGarcia It is a scalar under rotations; but just try a quick boost $v\rightarrow v'=v+a$ and you will see it is entirely frame dependent. Alternatively, if me and you are standing in a room at rest w.r.t each other, you see my KE as zero. Now start walking. What's my kinetic energy in your frame?
S Nov 23, 2012 at 14:09 history suggested Kitchi CC BY-SA 3.0
improved formatting of latex code
Nov 23, 2012 at 12:20 answer added Kitchi timeline score: 1
Nov 23, 2012 at 12:07 review Suggested edits
S Nov 23, 2012 at 14:09
Nov 23, 2012 at 11:12 comment added Jose Javier Garcia the kinetic energy is $ E_{k} = \frac{1}{2}m \vec v \vec v $ so is an SCALAR , an scalar does not depend on the reference ssytem
S Nov 23, 2012 at 8:32 history suggested Curious CC BY-SA 3.0
Equations are written in latex.some corrections are done.
Nov 23, 2012 at 4:28 review Suggested edits
S Nov 23, 2012 at 8:32
Nov 23, 2012 at 1:16 answer added Steven Ringo timeline score: 2
Nov 23, 2012 at 1:00 answer added Manishearth timeline score: 3
Nov 23, 2012 at 0:56 answer added Alfred Centauri timeline score: 17
Nov 23, 2012 at 0:50 review Close votes
Nov 28, 2012 at 3:02
Nov 23, 2012 at 0:40 review First posts
Nov 23, 2012 at 4:28
Nov 23, 2012 at 0:33 comment added Qmechanic Possible duplicate: physics.stackexchange.com/q/535/2451
Nov 23, 2012 at 0:30 history edited Qmechanic CC BY-SA 3.0
added link; retagged;
Nov 23, 2012 at 0:22 history asked geelen CC BY-SA 3.0