a)What happens to a window during a strong hurricane? Does it implode or explode and why?

b) A large boulder is thrown into a deep lake. As it sinks deeper, does the buoyant force upon it decreases or increases?

a. During a strong hurricane, depending on the window if it is open or closed, there can be an implosion. For instance, the windows are closed, strong winds collide with the window and it cause stress on the glass of the windows and an implosion occurs where the glass of the window collapse inward. 

b. If a large boulder is thrown into a deep lake, as it sinks deeper, the buoyant force upon it does not change because the boulder displaces the same amount of water no matter how deep it is in the lake. Since water is practically incompressible, its density is the same at all depths.