Their combined momentum after they meet is 0 .
        
             
        
        
        
I believe the answer is D. <span>The hypothesis is revised and another experiment is conducted.</span>
        
                    
             
        
        
        
Hmmm...maybe it would be because since you're staying still then things appear to go by quickly.
        
             
        
        
        
Mass of a sample of gas doesn't change, no matter what happens to its pressure, volume, or temperature.
        
             
        
        
        
Answer:
see below
Explanation:
First, the obvious, as you press the gas pedal harder the acceleration goes up as well.  Conversely, is you do not press the pedal, you will not accelerate.  This determines that is I press the gas pedal, it will CAUSE the car to accelerate.  This proves causation.
Now, correlation.  The definition of correlation in statistics is any statistical relationship between two random variables or data.  This simply means that these two events are connected to one another.  A POSITIVE correlation is when two correlated events move in the same direction as one another.  I have added a graph to help visualize this.  In this problem as the gas is pressed harder, the acceleration increases.  If the pressure on the pedal was decreased, then the acceleration also decreases.  If the pressure on the pedal is constant, the the acceleration is constant.
I hope this helps!