For sound waves in air with frequency 1000 Hz, a displacement amplitude of 1.2×10−8m produces a pressure amplitude of 3.0×10−2Pa. Water at 20∘C has a bulk modulus of 2.2×109Pa, and the speed of sound in water at this temperature is 1480m/s. a)For 1000-Hz sound waves in 20∘C water, what displacement amplitude is produced if the pressure amplitude is 3.0×10−2Pa?

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.

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.