You are assigned the design of a pressurized water tank for a future colony on Mars, where the acceleration due to gravity is 3.71 m/s^2. The pressure at the surface of the water will be 100 kPa, and the depth of the water will be 14.5 m . The pressure of the air outside the tank, which is elevated above the ground, will be 89.0 kPa . The tank's flat bottom has an area of 1.65 m^2, and the density of water is 1000 kg/m^3. Required:
Find the net downward force on the tank's flat bottom, of area 2.15 m^2, exerted by the water and air inside the tank and the air outside the tank.

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.

b. a lightning bug, plug of grass, and a worm

a. spokes of a wheel.

as indicated in the question radial contains rad, also found in radius, so the fracture's would span the radius.