Question

if you try to hold a glass with soapy hands, it's slips. why?

Answer 1

soap is used for reducing frictional force when we apply soap on a hand the frictional force is reduced which leads to very low frictional force between our hands applied with soap and the glass tumbler

Answer 2

it is because glass has a smooth surface.so there will be less friction and soapy hands also have less friction.so while holding friction is less so it tends to slip