Question

A sphere of iron and an another of wood, of the same radius, are held in water.Compare the upthrust on the two sphere

Answer 1

the sphere of iron will experience more upthrust because due to its heavy density it will sink down at the base of the river body.
And we all know that the upthrust increases as the depth increases so, at the base of the river body the upthrust will be more.
So the iron ball will feel more upthrust.

:-)