In theory speed haiwezi kuwa sawa kwa sababu ya centrifugal force na pia mambo kama ya density ya gases na earth core kuwa tofauti, hapo ndipo swali lako lilipozaliwa. Ila pia kwa sababu gases zina density ndogo, ni rahisi kubebwa na gravity. Gases zote ambazo zilikuwa nje ya gravitational field ya dunia zimesha escape nje ya atmosphere (actually zinaendelea ku escape at a very low rate at the very top of the atmosphere). Zilizobaki zipo under the influence of gravity.
Sasa basi, kwa sababu sehemu kubwa ya uzito wa dunia inatokana na the earth itself, na proportionally the atmospehere is not as dense/ heavy, speed ya earth inapungua negligibly ukiwa kwenye atmosphere. In fact ukienda chinibkabisa kwenye earth core kuna molten iron inayozunguka even faster. Mzunguko huu pamoja na magnetism na magnetic poles kuwa tofauti na axis ya dunia ndivyo vitu vunavyisababisha dunia kujuzungusha kwenye mhumikibwaje in the first place, ti answer anither question I saw here.
Kusema atmosphere inakwenda speed moja na earth (land) ni simolification kama vike kusema dunia inalizunguka jua.
Dunia hailizunguki jua. Dunia na jua vinazunguka point fulani ambayo inapatikana kwa kutumia Newtons laws na Einsteins Relativity na Keplers laws. Kwa sababu jua ni kubwa sana ukililinganisha na dunia, point hii inakuwa ndani ya jua, ingawa si katikati ya jua.
Lakinibkwa sababubtunataka kurahisisha mambo, tunasema dunia inalizunguka jua kwa sababu the difference is negligible.
Hata hiyo difference ya speed ya atmosphere iliyobebwa na dunia (land and oveand all the way to the core) na dunia proper yenyewe ni ndogo sana.