Rotational and translational equilibrium

[sgstudent]

When a ruler is placed on a pivot and I push it down from one side, then there is a moment. But then is there any linear movement? Since there is no translational equilibrium then won't there be a linear motion? Then how does rotational equilibrium come into play here?

 

[tiny-tim]

hi sgstudent!

When a ruler is placed on a pivot and I push it down from one side, then there is a moment. But then is there any linear movement? Since there is no translational equilibrium then won't there be a linear motion? Then how does rotational equilibrium come into play here?

i don't understand …

if you push it, it will change position …

where does equilibrium come into it?

 

[sgstudent]

hi sgstudent!


i don't understand …

if you push it, it will change position …

where does equilibrium come into it?

Oh sorry! I meant that when I push one side of a ruler on a pivot then I'll get a moment that is either clockwise or anticlockwise right? But since there only that downwards force acting on it, won't it mean that it does not have translational equilibrium?

 

[tiny-tim]

hi sgstudent!
(just got up :zzz:)

But since there only that downwards force acting on it, won't it mean that it does not have translational equilibrium?

ah!

but nature automatically supplies an upward reaction force at the pivot …

which exactly balances the downwards force! ​

 

[sgstudent]

Oh, I understand :-) thanks for the help!