List five situations in which a lesser amount of friction would be beneficial. overall, would a high or low coefficient of friction be in these situations?

1).  between parts of machine during Relative motion

2).  Rowing a boat in water

3). moving heavy mass on the surface

4).  Flying of aeroplane

5).  Transfer of liquid through pipe

Explanation:

As we know that friction resist the relative motion of two surface with respect to each other.

So here we require less friction in all above cases as we would like to transfer surface on another surface

Here we know that friction force is given as

so here in order to reduce the friction we need to decrease the value of coefficient of friction.

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.