A steel canister with a volume of 0.34 m3 is lowered to a depth of 800 m in the ocean.

a. What is the pressure on the canister in atmospheres?

b. What is the buoyant force on the canister?

a. Po + rho*g*D

rho is the density of sea water.
(Look it up)
D is the depth, 800 m
g is the acceleration of gravity, which you should already know
Po is atmospheric pressure at the surface, about 1.01*10^5 N/m^2

b. buoyant force = (rho)*g*V
V = the canister volume