I just verified this on my car scales. Equally raising both corners
increases the weight on the end that was raised. No surprise, Byron was
right.
-Curt
Randy Chase wrote:
> *warning....possible detailed techno-geek stuff follows*
>
> Iain Mannix wrote:
>
> > Raising/lowering/front/rear.
> >
> > Byron Short once used a big hammer to convince me that raising one end
> > of a car would make that end heavier. It is true.
>
> In what way did his hammer convince you? 8-)
>
> You can do it with
> > two bathroom scales and a sawhorse(or anything that is relatively
> > heavy that will not allow the mass to shift). Put two legs of the
> > sawhorse on one scale, call it the front. Put two legs of the
> > sawhorse on the other scale, call it the rear. Sit two
> > bricks/dictionarys/heavy things on the sawhorses over the legs.
> > Observe "front and rear" weight.
> >
> > Take the brick off the top of the sawhorse on the "front" scale, put
> > the brick *under* the legs of the sawhorse, raising the "front" three
> > inches(or however tall the brick is).
> >
> > There are still the same things on the scales - one sawhorse, two
> > bricks - but the weight will change; not total weight, but
> > distribution. It really works.
>
> Ian, I respectfully suggest that this is an incorrect method of
> demonstration. In one case, the scale is measuring roughly have the
> weight of the sawhorse, and part of the weight of the bricks, because
> the bricks load is shared by the sawhorse, and therefor distributed to
> both scales. When you put the bricks under the sawhorse, the main change
> comes from the one scale weighing 100% of the bricks, instead of have
> the load shared.
>
> I also disagree with the basic point, but I am willing to be shown in
> what way I am wrong. It has always been my grasp, that in order to do
> less work while appearing you are carrying the same load (hehe) when
> carrying sofas or other heavy furniture, you should raise your end. The
> higher end weighs less.
>
> This seems simple when viewed simply. If one takes a long heavy object
> and tilts it, eventually the higher end has almost no weight, and all
> the wieght is on the lower end. Now a car is a little more different, in
> that you didn't raise the entire car, you just changed it's location of
> mass and center of gravity. The tires still rest on the ground. There is
> also further complication because the higher end, though exhibiting
> slightly less force downward, will be affecting by suspension changes
> and the higher center of gravity.
>
> In any case, I was pretty sure that raising one end of a bar lightens
> it's load on that end. I did a quick test on a scale that confirms this.
> The higher end of the bar weighed less when I raised it.
>
> If I am missing something, please let me know what it is. I am not
> trying to debate the point, just understand why something I have thought
> for many years may be incorrect.
>
> Respectfully,
>
> Randy Chase
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