A wooden block of mass m and density is tied to a string; the other end of the string is fixed to the bottom of a tank. The tank is filled with a liquid of density
with
. What is the tension in the string.
Volume of the block . Now upthrust
weight of water displaced
weight of volume
of liquid
mass of volume
of liquid
. This is the upward force on the block due to buoyancy. The downward force on the block
its weight
The tension in the string is the net upward force on the block which is