4. A rope pulling on a block from the right
makes an angle 3 with the horizontal. If
the coefficient of friction between the
surface and the block is , how much
work is done by the tension in the rope
as it moves the block D meters to right
at constant speed? Let m be the mass of
the block and g the acceleration due to
gravity
O
Duong cos B
(usin + cos)
(Digcos)
sin
Duong sin
ucos 8 + sin)
Dmg cos ß sin B

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.