Figure below shows a uniform plank of weight 20N and length 1.0m balanced by a 0.5kg mass at a distance x from the pivot point O.

- Determine the value of X
- When the block is completely immersed in water the pivot O must shift by 0.05 m to the left for the system to balance. The density of water is 1000kgm
^{-3}

Determine:- The upthrust U on the block.
- The volume of the block.