And when the mountains are removed (81:3)

Almuntakhab Fi Tafsir Alquran Alkarim

The mountains are put in motion and vanish

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(81:3) when the mountains shall be set in motion, *3

And when the mountains are removed meaning

*3) In other words, the earth also will lose its force of gravity because of which the mountains have weight and are firmly set in the earth. Thus, when there is no more gravity the mountains will be uprooted from their places and becoming weightless will start moving and flying as the clouds move in the atmosphere.
 

And when the mountains are removed meaning in Urdu

اور جب پہاڑ چلائے جائیں گے