funny, actually, i'm a hydraulic, and pneumatic cylinder, pump, and line system mechanic, and the answer is pressure.... pressure builds up from the hydraulic pump, and then transfers through hoses to extend, and contract the cylinders by filling them with hydraulic fluid, and vice versa for contracting them.
hope this helps!
 
        
                    
             
        
        
        
Answer:

Explanation:
Acceleration is the change in velocity over time.

The object accelerates <em>from</em> 45 meters per second <em>to </em>10 meters per second in 5 seconds. Therefore, 

Substitute the values into the formula. 

Solve the numerator. 

Divide. 


The acceleration of the object is -7 meters per square second. The acceleration is negative because the object's velocity decreases and the object slows down. 
 
        
             
        
        
        
Turn lights off, unplug electronics, and use solar energy