Direction of Tension: FBD Down vs Up

[werson tan]

Homework Statement

why i figure b , the direction of FBD is in downward direction , whereas in a , its in upward directon

Homework Equations

The Attempt at a Solution

 

[DEvens]

Because in the two figures, you are looking at the opposite ends of the wire.

 

[werson tan]

Because in the two figures, you are looking at the opposite ends of the wire.

can you expalin further ?

 

[DEvens]

can you expalin further ?

Sure. Suppose we are each holding one end of a wire, and pulling as hard as we can. I am pulling to the left, say, and you to the right. So the wire is pulling me one way at my end. And the other end of the same wire is pulling you the exact opposite way at the other end.