Question for the resident boffins.....

[Big Dave]

regardless of centrifugal forces - I reckon the bike gets lighter when in motion because of the curvature of the earth. mass wants to keep going straight ahead away from the axis against the pull of gravity - thus making it lighter.

you'd need some pretty trick scales but.

[MSTRS:Me]

This is getting really heavy (no pun intended). If said bike could be put on a treadmill that was capable of giving a weight reading, then my theory could be tested.

[Highlander]

Duh. Course the bike gets lighter when it's moving. Nasa studies the phenomenum closely it is refered to as "FUEL BURN"

[MSTRS:Me]

Duh. Course the bike gets lighter when it's moving. Nasa studies the phenomenum closely it is refered to as "FUEL BURN"

Yes.....well.....OK

[Ixion]

but, but, but you are ignoring the Einsteinein effects. Theory of Relavity, mass increases as speed increases. So the faster it goes the heavier it gets.

Wadda ya mean , insignificant . I thought that all the litre sprotsbikers regularly got their knee down at near light speed?

[sAsLEX]

Theory of Relavity,

General or Special?

[scumdog]

Maybe that is why planes fly - they go so fast that they get really-really light and then they fly?????

[Ixion]

General or Special?

Well, both really. Einstein has said that all of the consequences of Special Relativity can be found from examination of the Lorentz transformations, and since the velocity/mass realtionship is part of the Lorentz transformations, it must be contained within the Special Theory. (ie the relationship is not affected by gravity). But the General theory is an extension of the special theory (or, the special theory is a subset of the General theory). So, both.

EDIT: mr = m0 /sqrt(1 - v2/c2) defines it.

[MSTRS:Me]

Well, both really. Einstein has said that all of the consequences of Special Relativity can be found from examination of the Lorentz transformations, and since the velocity/mass realtionship is part of the Lorentz transformations, it must be contained within the Special Theory. (ie the relationship is not affected by gravity). But the General theory is an extension of the special theory (or, the special theory is a subset of the General theory). So, both.

F... me - would you like fries with that?

[sAsLEX]

Well, both really. Einstein has said that all of the consequences of Special Relativity can be found from examination of the Lorentz transformations, and since the velocity/mass realtionship is part of the Lorentz transformations, it must be contained within the Special Theory. (ie the relationship is not affected by gravity). But the General theory is an extension of the special theory (or, the special theory is a subset of the General theory). So, both.

True, just doing some light reading of Hawkings a Universe in a Nutshell at the mo, his sense of humour is quite a laugh

[Highlander]

Me thinks you'd hear some interesting concepts if you raised this question around the camp fire at a rally when fuelled by a few ales....

[Sniper]

Lets put it this way. If you weighed your bike when it is stationary and the scales showed say 200lb you would get a lighter weight if you rode over the scales. The faster you went over the scales the lighter the weight would be.

There's a formula for this just not too sure what it is.

Until you went too fast and flew over the scales.

[merv]

If your bike weighs say 200kg wet and you weigh 100kg also wet, then the total weight is 300kg and it remains that weight no matter how fast you go within the realms of the speed the bike can go that is. There is no way the bike can become lighter with speed at the contact points unless you go over a jump.

Or unless like Big Dave says because of the earth's curvature, but no bike can go fast enough to make much of a difference. If I could be bothered finding the time I could work that out for you.

Also taking the theory of relativitiy, as I've never been that fast I'm not sure what happens as you approach the speed of light. I've heard it slows down time, but I'm not sure about weight.

In basic engineering design the opposite is actually allowed for in that the live loading (i.e. at speed) is always increased over static loading. What I'm talking about here is loadings on bridges for example of traffic going over them where extra is added for impact of live loads i.e. the assumption that increased forces are applied at joints, bumps etc. The motorcycle designers would do the same in designing the strength of their wheels.

Any feeling of lightness when on the move is all about the gyroscopic effect of the wheels making the bike want to stay going as it is.

[Pixie]

Lets put it this way. If you weighed your bike when it is stationary and the scales showed say 200lb you would get a lighter weight if you rode over the scales. The faster you went over the scales the lighter the weight would be.

There's a formula for this just not too sure what it is.

Skyryder

No,you've got it all wrong.
The faster you rode over the scales,the shorter you and your bike will become,foreshortened in the direction of motion,and the more massive you and the bike will become.

[merv]

Going on about scales, the only reason they might read less is they are too bloody slow in their mechanism, but any decent in motion weighing system would read the correct weight in a tiny split second and it won't be any different than stationary.