When you stand on a scale, the scale pushes up to support you, and the
scale reading shows the force with which it’s pushing. If you stand on
a scale at Earth’s equator, is the reading greater or less than your weight?
F→scale + F→g = ma
That's my guess.
The Attempt at a Solution
Well, I'm reading it in the book. It's an example with the answer that the scale reading will be less than my weight. But I still don't understand how that works out to be.
So, a scale is pushing back the same force that's going into it? And it notices how much weight it has to balance, thus say it's balancing 81.81 kg so, about 801N is being pushed into the scale and the scale is pushing back out about 801N? What?
I really don't get this.
The only two forces acting on you are the downward
force of gravity and the upward force of the scale. For them to sum
to a net force that’s downward, the force of gravity—your weight—must
be larger. Therefore, the scale reading must be less than your weight.
ASSESS Make sense? Yes: If the two forces had equal magnitudes, the
net force would be zero—inconsistent with the fact that you’re accelerating.
And if the scale force were greater, you’d be accelerating in
the wrong direction! The same effect occurs everywhere except at the
poles, but its analysis is more complicated because the acceleration is
toward Earth’s axis, not the center.