Suppose the glass of the previous problem is covered by a jar and air inside the jar is completely pumped out a. What will be the answer to the problem? b.Show that the answers do not change if a glass of different shape is used provided the height, the bottom area and the volume are unchanged.

Answer

A, D

Explanation

If the glass wil be covered by a jar and the air is pumped out the atmospheric pressure had no effect so
a. Force exerted on the bottom
`=(hrho_ug)xxA`
`=(20xx10^-2xx10^-3xx10)20xx10^-4`
=4N`
b. `mg=hxxrho_wxxgxAxxF_s`
`rarr F_s=5-4=1N`
`c. If glasses of differet shapes used have the same volume height and area no change in answer will occur.