What is pushing upwards on your body while you are standing still?

Answer 1

That's an excellent question.

As a student of Physics, you know that in order for your body to be not accelerating,

the forces on you have to add up to zero. You know that the force of gravity is pulling

you down, and you want to know what other force there is that's canceling out gravity,

so that they really do add up to zero.

The answer is:

It's the force of the floor pushing up on the bottom of your feet, with a force that's

exactly equal to your weight.

You can measure that force like this: Put a tiny mirror on the floor. Then take the

bathroom scale, turn it over, and set it down on the floor upside down, so that

you can read the numbers in the tiny mirror on the floor. Carefully stand up on

the bottom surface of the scale. Now the scale is measuring the floor's upward

force on the bottom of your feet. What does it read ? See ? What did I tell you.

Anther perfectly good way to think about this:

The forces of gravity always work in pairs. Two masses always attract each other

with equal forces. The force that attracts you toward the center of the Earth is

what you call "your weight on Earth".

Nobody every talks about the other one ... the force that attracts the Earth

toward the center of you. The two forces are equal. It's perfectly correct to

call the other one "the Earth's weight on you", and you just measured it with

the upside-down bathroom scale.

Answer 2

weight