Question

Define: why does a block of wood held under water rise to the surface when released

Answer 1

Hi here is your answer,
Weight of the wood is less than the weight of an equal volume of water so when it is completely submerged the upward buying force on it is created than the downward gravitational force. therefore the wood rises to the surface when released.

Answer 2

Answer:

When a block of wood hold under water it rises to the surface of water after release because density of the wood is less than the density of the water.