Question

We know that who has mass can exist in the space. But there are some particles who are massless, yet they are in space. HOW ??​

Answer 1

Answer:

Explanation:firstly mass is any thing tha has weight and can occupie space.

secondly: science has made us to understand that everything on earth has mass,but even if it is massless just like in your guestion. it will still be in space because their is a gravitational froce underground that pulls it to earth.

Answer 2

Now whatever we have studied about mass is correct but something modification required.

I know you have read

What is mass?

Amount of matter contained in a body

This is the one thing which made confusions

Mass is different for a body in motion and for a body in rest

To know whatever I said is right ,

you need a tennis ball or a cork ball or a stumper ball then you first hold it and feel its mass and then if possible try to catch that ball being hit by a cricketer straight to you,

when you will catch that same ball (this time you know that it is in motion) you will feel pain in your hand

Now you can observe that when the mass is in rest is something different but when in motion mass is something different

As in the above case when the mass is at rest you didn't feel pain but when mass is in motion you feel pain as if mass increases with velocity

Therefore for this reason it has been divided into two types

1. Rest mass
2. Relativistic mass

1. Rest mass- it is the amount of matter contained in a body when it is at rest.
2. Relativistic mass-it is the mass of a body in motion

Hence a body when it is at motion is said to have no mass it means is doesnot have rest mass mainly photons

If you will give the example of human being then it has rest mass as well as relativistic mass

example-we can run(Relativistic mass) and then after sometimes can come to rest(rest mass) if you measure you can determine the mass in both cases

But in case of photon there is no rest mass but only there is relativistic mass