What is the direction of buoyant force?

An air bubble of radius $1\,cm$ in water has an upward acceleration of $9.8\,cm\,s^{-2}$. The density of water is $1\,g\,cm^{-3}$ and water offers negligible drag force on the bubble. The mass of the bubble is $.......g$.
$(g = 980\,cm\,s^{-2})$

$A$ rectangular block of size $10 \,cm \times 10 \,cm \times 15 \,cm$ is floating in water with the $10 \,cm$ side vertical. If it floats with the $15 \,cm$ side vertical,then the level of water will ..........

$A$ sphere of solid material of relative density $9$ has a concentric spherical cavity and floats just submerged in water. If the radius of the sphere is $R$,then the radius of the cavity $(r)$ is related to $R$ as:

An ornament weighs $10\, g$ in air and $6\, g$ in water. The density of the material of the ornament is $20\, g/cc$. The volume of the cavity in the ornament is ........ $cc$.

The spring balance $A$ reads $2 \, kg$ with a block $m$ suspended from it. $A$ balance $B$ reads $5 \, kg$ when a beaker filled with liquid is put on the pan of the balance. The two balances are now arranged such that the hanging mass is inside the liquid as shown in the figure. In this situation: