# Water pressure question

hi, i'm stuck on a homework task i've been given..help will be greatly appreciated setup is as follows:
image 1 . a tube (1ft diameter) submerged in water. tube is filled with air-filled balls( 1ft diameter) which tightly fit all the way in the tube, leaving only small water pockets in between.

image 2. same tube. solid object , no water gaps.

at 10ft depth, what would be the pressure that will have to be exerted on the uppermost ball in order to push the first ball out of the tube . i cant understand the buoyancy issue...??will it be equal to the sum of the buoyancy forces of all the balls?or will it be the pressure (kg/cm2) at a depth of 10ft. ...bit of a mess:)

what will be the difference if the shape was like that in image2? i want to calculate what would be the force to push the object 1ft deeper into the water outside the tube??

thank you
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution