Because it's the basis of how everything around you works
        
             
        
        
        
When the parachute deploys it increases the persons air resistance to (temporaily) greater than the force of weight. This causes them to decellerate. As they decellerate resistance decreases again until once again it balances out. Terminal velocity is reduced to a safe level, and landing without injury is possible.
        
             
        
        
        
When the roller coaster going down
step by step
        
             
        
        
        
Answer:
The total electric flux through the two surfaces is equal.
Explanation: