8) A boy pushes a large 60kg box across the floor so that it accelerates at .5m/s2. He has his arms angled up from the horizontal at 10° as he applies a 100N force. What is the magnitude of the
kinetic friction coefficient between the box and the ground?

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.

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it