physics

[habib123]

why do we have to suspend the plumb line freely?
is it so that it comes in line with its center of mass?

 

[Zohaib Sherazi]

Yes. We need the exact direction in which gravity points.

 

[hassam]

to ensure dat there is no friction between the pivot and plumbline so that the card or whatever the object is in equlibrium

huh one thing to add that this will ensure that the c.o.g is behind the plumbline

hey zohaib how we shud position our eye when lookin at plumbline

 

[Zohaib Sherazi]

That won't be too important here but position it perpendicularly.

 

[habib123]

thanks mate zohaib what do u do man

 

[Zohaib Sherazi]

AS

 

[shamil]

remember it should be free so that there is no friction between the thread and the hoder, thus it will on its own come to settle with the centre of gravity lying just behind it. then another point is used nd this line is intercepted and this interception is known as the centre of mass.
The eye should always be perpendicular to the thread this increases accuracy of result by reducing the chances of parallax error.