Which device for controlling lift allows air to flow from the lower surface to the upper surface at high angles of attack?

Slat

Explanation:

In the field of aero-space engineering, there exist a system that produces an increased amount of lift produced by the aircraft's wing. This mechanism is know as a high lift device.

The device could either be movable or fixed. types of movable devices are flaps and slats and fixed devices are leading edge root extensions, slots and boundary layer systems.

The slat is a small aerofoil shaped device which pushes the airflow from the lower surface  the upper surface when at a high angle of attack.This pushes airflow at the front of the wing and also allows the wing to be operated at the higher angles required to produce more lift. The gap between a slat and a wing is a slot.

two charges are fixed in place on the x-axis as shown. the charge at x = 0 is negative and has magnitude q = 2 μcoulombs (1 μcoulomb = 10-6 coulombs). the charge at x = d, (d = +12 cm), is positive and has magnitude q = 4 μcoulombs. find a point x = xo along the x-axis at which the electric field is zero.

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.