When the wood block is dropped in the water and settles so that it floats and is no longer bobbing up and down, how do the buoyant force and gravity compare?

Buoyant force equals in magnitude the force of gravity on the wood block

Explanation:

When the object stops bobbing and floats, its weight (force exerted by gravity) equals the magnitude of the buoyant force (which in magnitude equals the weight of the fluid -in this case water- displaced by the object), but are in opposite directions so they cancel out and renders a zero net force.

When the wood block floats, its buoyant force equals in magnitude its weight (force exerted by gravity)

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

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