During the dark ages-All that wasn't around the christian religion were lost. Knowledge and discoveries before the Dark Ages were mainly in Greek ideas. Biblic scripts however were in Latin. Therefore all inventions up to the dark ages were lost and only religious scripts preserved in the churches. Outside the church, no one knew how to write, read or even communicate.
Answer: The momentum of the child and milk together is 58.125 kg.m/s
Explanation:
Momentum is defined as the product of object's mass and velocity.
Mathematically,

where, p = momentum
m = mass of the object
v = velocity of the object
In the given question, we are given that a child of mass 21.0 kg is carrying a gallon of milk having mass 2.25 kg and running with a velocity of 2.5 m/s. Hence, the momentum by both milk and child will be:
....(1)
Given:

Putting values in equation 1, we get:

Hence, the momentum of the child and milk together is 58.125 kg.m/s
Answer:
Difussion
Explanation:
Diffusion is the result of a totally random phenomenon in which the molecules of a fluid come and go between two vessels that can be connected by a pipe. These molecules travel in a single direction, where the solute is more concentrated to where it is more diluted.
This movement of particles will be modified according to the length or area of the pipe and the concentration of solute. The greater the difference in solute concentration along the tube, the greater the diffusion
The motion of molecules in a ice cube are so packed together that they can't move freely like molecules in liquids and gases