Making a Plum-Bob & Its Uses: Explained!

[celco]

Hello

I have to Explain how a plum-bob can me made and what it is used for? can anyone tell me this, i know what it is used for but i do not know how once can be made...

I also need to know why it is said that a plum-bob always points towards the centre of the Earth ? Please Help

 

[HallsofIvy]

A plumb-bob is simply a weight- take anything that has weight and tie a string to it. A plumb-bob always points toward the center of the Earth because of gravity- it is pulled down!

(I'm moving this to "Introductory Physics")