The correct answer to this question is this one:
By definition, if a molecule is composed of two hydrogen atoms and one oxygen atom, that molecule is a water.<span> In fact, the structure of water is written as H20, which signifies that two hydrogen (H) atoms and one oxygen (O) atom make up the molecule.</span>
It does not.
The speed at which the earth rotates determines the length of the day.
Answer: -4.4 m/s
Explanation:
This problem can be solved by the Conservation of Momentum principle, which establishes that the initial momentum 
must be equal to the final momentum 
:
(1)
Where:
(2)
(3)
is the mass of the child
is the initial velocity of the child
is the mass of the adult
is the initial velocity of the adult (it is sitting still)
is the final velocity of the child
is the final velocity of the adult
Substituting (2) and (3) in (1):
(4)
Isolating :
(5)
(6)
Finally:
This means the velocity of the child is in the opposite direction
