Question

A piece of wood is held under water. The upthrust on it will be a. Equal to the weight of wood piece b. Less than the weight of the wood piece c. More than the weight of wood piece d. Zero EXPLAIN THE ANSWER TOO

Answer 1

more than the weight of the wood ..... because the wood block is stationary... so there must be an equal and opposite force acting on the wood upwards.
This force is equal to the sum of the weight of the wood and the external force applied on the wood to keep it under water.
So, obviously, the upthrust is more than the weight of the wood