Science & the humble bathroom scale

[efab]

what a wonderful topic to brighten up my day

well done to all and it has been a very good education both to me and my trainer at the gym

[blackpete]

Mffffffft heheheheh.

I got busted by my 5th grade teacher for ruining her science experiment.
She showed us that air had weight by putting a balloon on a beam balance with a weight at the other end. The class was in awe until I asked her to let the air out of the balloon and repeat the experiment. I demonstrated that all she was weighing was the balloon.
The class laughed and I was on an express ticket to the principals office.

Fat bitch she was too. I bet she still thinks the laws of thermodynamics don't apply to her.

If the scales are sensitive enough there will be a difference in a inflated balloon and deflated as done in that experiment.

[blackpete]

I learned about C of G during my pilot training, I found it highly unusual that the accepted (72 Kg?) theoretical weight of a passenger is vastly different than the actual weight of most passengers therefore leaving C of G calculations wide open to devistating error.

I was a passenger in a Caribou that took longer than usual to get of the ground, this was due to wet camaflage nets.

[blackpete]

Good load cells are accurate reliable & extremlly robust. At work we've got several Bogballe 2.5t fertiliser spreaders, they've got a 5 tonne load cell & after 6yrs & thousands of tonnes of fert are still accurate, the zero point (tare) gets reset needed.
With the hopper linkage set up all the wt is supported by the load cell which is attached to the front of the hopper & the spreader chassis, but it doesn't matter where the fertiliser is in the hopper front or back strange as it may seem the load cell reads the same.

RE scales weighing the atmosphere above, for scales to do that the weighing platform needs to be isolated from the atmoshpere on one side ie a barometer, in a normal scale due to air being a fluid the is equal pressure all round the platform. in a vacum it should weigh minutely more, because in the air there would be a slight pressure diffurence between the top & bottom of the plate.