Answer:
There is no Buoyant force.
The block will only float to the surface when the pressed face is released
Step-by-step explanation:
There would be no Buoyancy force on the cube of Oak wood when one face is pressed flat against the Bottom of a tank and this is simply because there is no upward force acting on the side of the cube that is pressed against the bottom
Buoyant force is simply caused by the pressure difference between the water over and under an object immersed in water . hence since there is no water pressure under the immersed cube there will be no pressure difference between the water under and over the cube of oak wood immersed in the water.