Aprinted circuit board (pcb) is supported by a chassis that is attached to a vibrating motor. the board is 1.6 mm thick, 200 mm wide, 254 mm long, and has a mass of 0.6 kg. neglect damping, model the board as a doubly clamped beam, determine its stiffness and natural frequency, and compute the displacement transmissibility if the chassis vibrates at 60 hz due to motor unbalance. the board is made from e poxy fiberglass for which e = 1.38 x 10^10 n/m2

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.