0
$\begingroup$

A weighing machine measures the normal force applied by an object. However 2 forces act simultaneously on the machine ( normal and mg ) Under normal conditions (a=0) N=mg . So this would mean that a force a equivalent to 2 mg or 2N is being applied on the machine not just N. What's wrong with this ? It's said that a weighing Machine( hereafter referred to as machine) measure the normal force applied by the body on the machine . But when a body is standing on machine 2 forces act simultaneously (namely the normal force and gravity) . At rest N=mg. So forces applied at the machine = 2mg (N+mg). This is contradictory to the statement 1 . Please Explain in detail It's said that a weighing Machine( hereafter referred to as machine) measure the normal force applied by the body on the machine . But when a body is standing on machine 2 forces act simultaneously (namely the normal force and gravity) . At rest N=mg. So forces applied at the machine = 2mg (N+mg). This is contradictory to the statement 1 . Please Explain in detail

Improve this question
$\endgroup$
3
  • 1
    $\begingroup$ Does this answer your question? Why do scales measure normal force not weight? $\endgroup$
    – Farcher
    Commented Dec 16, 2023 at 16:45
  • $\begingroup$ A spring scale hangs an object on a spring. The force of gravity pulls the object down, stretching the spring. The amount of stretch tells you measures the amount of force from $F = kx$. And the force tells you the mass from $F = mg$. So the scale directly measures force and indirectly measures mass. $\endgroup$
    – mmesser314
    Commented Dec 17, 2023 at 1:26
  • $\begingroup$ A pan balance is another kind of scale. You put an object in one pan and known masses in the other. When the masses are equal, the scale is balanced. Again, the force of gravity is responsible for making the scale balance. But this is a more direct measure of mass. Unlike a spring scale, if the force of gravity gets stronger (in a valley, closer to the center of the Earth) or weaker (on a mountain), this scale doesn't give a false reading. $\endgroup$
    – mmesser314
    Commented Dec 17, 2023 at 1:30

1 Answer 1

Reset to default
2
$\begingroup$

A scale or weighing machine measures the compression of a spring (or strain in a beam, or some equivalent sensing device) caused by the weight of the object downward on one side, and the equal and opposite normal force upward of the ground or surface it's resting on, on the other side.

Improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.