Question

Two blocks are having same mass but are made up of wood and iron respectively. The blocks are kept submerged into the water as shown by some external force then___

• A. upthrust on iron will be more than wood.
• B. upthrust on wood will be more than iron.
• C. both will experience the same upthrust as weight of the blocks are same.
• D. the upthrust cannot be compared.

Answer 1

The correct option is B. upthrust on wood will be more than iron.

Upthrust depends on the volume of the submerged block and the density of the displaced liquid. So, the more the volume of the body submerged, the more the upthrust. Here, the liquid is the same but the volume of the wood is greater than that of the iron block. Hence, the upthrust on the wooden block will be more than that on the iron block of the same mass.