Changes

: [[Upthrust]] is weak in the [[air]] because the [[air]] is not very [[Density|dense]]. For most [[object]]s in [[air]] [[upthrust]] can be ignored because it is so small.

: [[Upthrust]] is caused by the [[pressure]] in a [[fluid]]. [[Pressure]] increases with [[depth]] so the bottom of an [[object]] will experience more [[pressure]] than the top. This difference in [[pressure]] results in a difference between the [[force]] on the bottom and the top, known as [[upthrust]].

===Examples===