The rotating blades of a hovering helicopter sweep out an area of radius 4m imparting a downward velocity of 12m/s to the air displaced. A) find the mass of the helicopter.
B) the speed of rotation of the blades of the helicopter is increased so that the air now has a downward velocity of 13m/s. find the upward acceleration of the helicopter

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered

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.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.