Crying is a signal of distress to babies.
Some reasons why babies cry: The baby is not feeling well, strange feeling that needs nappy change, a feeling of hot or cold, a feeling of tired and needs rest, a feeling of cuddling, feel like crying, and a feeling of hungry.
Electromagnetic waves are the waves that can travel without a material medium.
Answer:

Explanation:
From the Question we are told that
Mass of A and B is 60kg
Speed of A=2m/s
Speed of B=1m/s
Mass of bag =5kg
Generally the momentum of the astronaut A and bag is mathematically given as


Generally to avoid collision the speed of astronaut be should be less than or equal to that of astronaut A with the bag
Therefore for minimum requirement speed of astronaut A should be given by astronaut B's speed which is equal to 1
Therefore


Producers to primary consumers to secondary consumers to tertiary consumers to carnivores