When a 40N force, parallel to and directed up the incline, is applied to a block on a frictionless incline that is 30o above the horizontal, the acceleration of the block is 2.0 m/s2, up the incline. Find the mass of the block.

5.8 kg

Explanation:

We are given that

Force,F=40 N

Acceleration,a=

We have to find the mass of block.

Where

Explanation:

GIVEN:

applied force up the inclined plane,

angle of the plank from the horizontal,

acceleration of the body up the plane,

Now from the  schematic we balance the forces:

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.