(1) i want to know how much pressure is generated when we stand on ground. pressure = force/area . force is mass x acceleration . do we need to take acc. as 9.8 or 0 .
(2) is the weight measured on a is the 'pressure' of an object or the person bcoz weight of mass can be zero depending on gravity.
(3)what is the formula for ?
(2) The weight measured is not the pressure, it is the force being applied by the person on the ground, thats why the weighing machine will show different values on different planets. And you can't say 'weight of mass', they are different terms.
(3) The formula for weighing something is
m=mass of object
g=gravity or acceleration due to gravity
Plz mark as brainliest :D
Scales measure how much something weighs—and they do it by measuring how much force exists between the object you're weighing and planet Earth. Although scales measure force, they give you measurements of mass in kilograms, grams, pounds, or whatever.वन्देमातरम्
What you feel as 'weight' isn't exactly the gravity, but the force which acts on your body to counter the gravity. When you're standing on the ground, gravity acts on each and every particle in your body depending on the mass of that particle (hence it is a body force). However, the reactionary force from the ground acts only below your feet (hence it is a surface force). This reactionary force then gets transmitted throughout your body in the form of compressive and shear stress, which gives you the feeling of weight. During freefall, there is only gravity acting on your body, but nothing to provide the reactionary force to counter it, and hence you feel weightless.
On a side note, when you are inside a rocket accelerating upwards, the reactionary force on your body is much larger than the gravity, which results in much stronger compressive and shear stresses on the individual organs of your body. This results in the feeling of extremely large weight.
Why don't we feel the weight of such a huge amount of air on us?
The main misconception here seems to be about the behaviour of air molecules and the resulting air pressure. We start off with an example:
Suppose that your palm is open, outstretched, surrounded by air. Atmospheric pressure is about 105105 Pascal. A human palm (roughly) has a surface area of about 100 sq.cm. Now, the resulting force due to the air above you, on your palm is 105∗100∗10−4N=1000N105∗100∗10−4N=1000N. That's about the same as a 100 kg block on top of your palm. So why don't we feel it? And even if we do, then why does another 1 kg block on it feel soheavy?
The answer is that the air above your palm pushes it down, but the air below your palm also pushes it up. This balances the weight, so you don't feel as if you're holding a 100 kg block. So, in a way, you are lifting up air, but air is also lifting you up.
This might seem a bit absurd if you're learning something about air pressure for the first time. We have this false notion that since there is a lot of air above, it should be pushing us down. This is incorrect, however. Air has pressure because its molecules move at high speeds (as high as 500 m/s!) and collide with all surfaces in contact. Since they move randomly in all directions, they exert equal pressure in all directions. See Kinetic theory. If you still can't convince yourself about this, think of what is holding the air above when your palm is not there. There is only the air below to support its weight. That same air below is now supporting your palm. The same concept is applicable to your entire body, so you don't feel being pushed down by tons of air. Similarly, swimming below a ton of water is not the same as holding a ton of water on your back.
Now, we come to the other part of this question (which is not your actual query, I suppose). If air is pushing us from all sides, shouldn't our body collapse? No. This is because the blood flowing in our body provides counter-pressure. The skeleton also prevents it from collapsing.
Our bodies are accustomed to the usual atmospheric pressure of 1 atm. If the surrounding pressure is too high (like in deep sea) or too low (like in space) than this, then the forces acting on your skin from inside and outside will not be balanced, and your skin will be ruptured, often leading to death. In fact, strong winds can even rupture the delicate skin of our nose and ears and cause bleeding sometimes (mostly in babies).