Is Your 42 kg Scale Reading Accurate in Different Gravitational Fields?

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A scale reading of 42 kg accurately reflects mass, but weight varies based on gravitational fields. On Earth, a mass of 42 kg translates to a weight of approximately 411.6 Newtons or 92.5 pounds. Weight measurements can be affected by factors such as friction and the scale's calibration, potentially leading to slightly lower readings. In different gravitational environments, like the Moon, the same mass would weigh significantly less, demonstrating that weight is contingent on gravity while mass remains constant. Understanding the distinction between mass and weight is crucial for accurate measurements across varying gravitational fields.
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if our weight is 42 kg in a weighing machine , in reality is it more or less than 42 kg?
 
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If a machine measures your weight to be 100 lbs, and the machine is not accelerating (at any rate, not accelerating quickly), and there are no extenuating circumstances, and the machine is well-oiled and frictional forces are neglible, and if the weighing machine measures correctly (that is, it doesn't measure the same weight differently depending on how much weight is already on it)... then I would say it's probably exactly right.

If the machine is more realistic, I guess it depends on how the machine's made.

I imagine most real machines get your weight a little low, due to frictional forces. Plus, they probably sell more scales that way.
 


Adding to the previous post, I know that some food service scales and postal scales have a zero weight calibration feature, which helps accuracy of a weighted measurement.
 


DrChem said:
if our weight is 42 kg in a weighing machine , in reality is it more or less than 42 kg?

"Mass" (represented in kg’s) refers to a “quantity of matter”. Therefore, our “weight” is merely a consequence of the gravitational field in which our mass is placed and then “weighed”.

On the moon, we‘d weigh roughly 6 times less than on the surface of the Earth, but our “mass” would be identical in either location, just as our “mass” would remain identical if we were placed anywhere else in the universe.

Weight is therefore defined by:

w = mg

where,

weight (in Newtons) = mass (in kg) x gravity (in m/s^2, which is 9.8 m/s^2 on Earth)


For instance, if your “mass” were 42 kg, on Earth you’d weigh:

42 kg x 9.8 m/s^2 = 411.6 Newtons (or 92.52768 pounds)


Pounds = .2248 x Newtons
 
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