The word to fill in the blank is "equal". Because the time taken to rotate (spin on its axis) is equal to the time of revolution (going around the earth), this means that both have the same rate of angular rotation. So for every bit that the moon goes around its orbit around earth, the moon itself rotates accordingly to present the exact same side to earth.
Answer:
Part a)
h = 0.86 cm
Part b)
Level will increase
Explanation:
Part a)
Mass of the ice cube is 0.200 kg
Now from the buoyancy force formula we know that weight of the ice is counter balanced by buoyancy force on the ice
So here we will have



now as we know that ice will melt into water
so here volume of water that will convert due to melting of ice is given as


So here extra volume that rise in the level will be given as



Part b)
Since volume of water that formed here is more than the volume that is displaced by the ice so we can say that level of liquid in the cylinder will increase due to melting of ice