Where Will the Thread Break When a Stone Hangs by a Fine Thread?

[iampaul]

Homework Statement

A stone hangs by a fine thread from the ceiling and a section of the same thread dangles from the bottom of the stone.

Homework Equations

a. If a person gives a sharp pull on the dangling thread, where is the thread likely to break: below the stone or above it?
b. What if the person gives a slow and steady pull?
Explain your answer.

The Attempt at a Solution

I think that the answer for a is below while for b the answer is above, but I don't know exactly how. Can someone please explain this in detail. Thanks

 

[PeterO]

Homework Statement

A stone hangs by a fine thread from the ceiling and a section of the same thread dangles from the bottom of the stone.

Homework Equations

a. If a person gives a sharp pull on the dangling thread, where is the thread likely to break: below the stone or above it?
b. What if the person gives a slow and steady pull?
Explain your answer.

The Attempt at a Solution

I think that the answer for a is below while for b the answer is above, but I don't know exactly how. Can someone please explain this in detail. Thanks

have a look at the tensions in the string, if the stone has a mass of 10kg, and a second 2 kg stone was attached to the bottom of the lower string.

What happens to those tensions is the 2 kg stone is replaced by a 4kg stone? 6kg? 8kg? 12kg? 14kg? ...

That should give you a clue for part (b)

Answer me that and I will give you a hint about (a)
EDIT: for speed of calculation, and because each stone could have been a little heavier any way, use g=10 m/s^2