The upward force that makes corks, or any substance or object, float is called buoyancy.
Oil is denser than cork, so the cork would float.
A cork has a low density. It is lower then water. That causes it to float.
The force that helps a ship float is the buoyant force. The buoyant force is exerted by a fluid upwards that opposes the weight of the object immersed.
The force that is at work is gravity. If you are thinking of bouyancy, it is not a force.
The force that makes things float is called buoyancy.
water resistance
Buoyancy.
Yes.
The weight must be less than the buoyant force. Push down on a floating cork and it will sink below the surface. Stop pushing and remove your hand, and the cork's buoyancy will take over and the cork will float again.
gravity
a dingaling