An iron ball is suspended in the air by a string attached to the ceiling. This iron ball is then submerged into the a beaker of water on top of a measuring balance, such that the ball is not in contact with the base of the beaker. When the beaker of water(without anything in it) is measured with the balance, the reading on the balance is W. What is the reading on the balance with the suspended ball in it?
The Attempt at a Solution
T= tension of the string
mg=weight of ball
u=upthrust due to the weight of ball displaced by the water
Since this system is in equilibruim, it can be taken that nothing has been added into the beaker of water. So, the reading on the balance with the suspended ball in it should be W.
But the answer given is W+U. Can anyone tell me what i have done wrong? Is there anything wrong with my assumption? Or is the answer really wrong? Help~~~~~