Does Bouyant Force Affect Scale Readings?

[twilos]

Homework Statement

Before you submerge a block (25N) in water, you place the container of water on a scale. The scale reads 100N.

You then immerse the block in the water, the block is also hung on a scale that reads 17N. Is the scale reading greater than, less than, or equal to 100N? ( Assume that the object does not touch the sides or bottom of the container at all.)

http://i5.photobucket.com/albums/y156/twilos/NewBitmapImage-4.jpg

Homework Equations

F=ma

The Attempt at a Solution

I believe the scale will read more even though if you do a Free Body Diagram of the Block its:

buoyant Force + Tension of Scale - Weight = 0
buoyant force = Weight - Tension
buoyant force = 25N - 17N = 8N UpWard

So the Weight of the block is canceled out by the buoyant Force + Tension. However if you think of it intuitively, if the tension of the block is not fully supporting the block itself the buoyant force will take into account weighing down the scale at the bottom therefore it will be Greater than the 100N originally. But maybe I am wrong can someone help me out this is very tricky =) Thanks again

 

[LowlyPion]

You seem to have it.

The block displaces water. 8N worth of water. It's as though there is an additional 8N worth of water in the box isn't it? So ...

 

[twilos]

so i am right!? awesome it does weigh more because the water displaced is 8N worth also right?