Answer:
When air resistance equals the weight of an object, the object has reached free fall.
Explanation:
- When an object has only force acting on it as gravity then, it experiences free fall.
- During free fall all the forces except gravity is balanced by one another.
- In the question, object's weight is balanced by air resistance so it is in the state of free fall.
- At the null point of free fall, object experiences weightlessness i.e. it feels like object is not attracted by any force.
The answer is; Irregular.
Answer: addition of electrons and hydrogen ions. loss of electrons and addition of hydrogen ions. loss of electrons and either addition or loss of hydrogen ions.
If the billiard ball is going at the constant speed and contains its mass then the momentum WONT be changing. But realistically you have external forces like friction and air resistance changing the velocity thus changing the momentum. In this case momentum is not conserved because you're introduction an external force.