Krishna is trying to push an empty airtight bottle into a beaker full of water. As he tries to push it further down into the water:

In a fluid, the buoyant force acting on a submerged or floating object always acts _________.

A ship floats on water because:

When an empty plastic bottle with an airtight stopper is pushed deeper into a bucket of water, the increasing upward force that resists the downward push is known as __________.