Answer:
you need to consider the use for the product, how brittle the materials are, how they react to certain things, the cost of the materials, the durability and flexibility of the materials, and how easy to obtain the materials are as well as how they would work and how they would hold
 
        
             
        
        
        
Wind farms, solar collectors, and nuclear power plants generate no pollution.
But wind farms make noise, wind and solar are both hazardous to birds, and there's no known means of disposing of nuclear plant waste that's completely safe.
        
             
        
        
        
Sound waves are known to be the one that's not considered as a type of electromagnetic energy. As for microwaves and x-rays, they tend to share the same frequencies that can be considered as electromagnetic, and sound waves have a different frequency than them.
        
             
        
        
        
The outer planets have a high gravity due to their large size
        
                    
             
        
        
        
Answer:
<em>Answer: positive velocity & negative acceleration</em>
Explanation:
<u>Accelerated Motion</u>
Both the velocity and acceleration are vectors because they have magnitude and direction. When the motion is restricted to one dimension, i.e. left-right or up-down, the direction is marked with the sign according to some preset reference.
The locomotive is moving at a certain speed with a (so far) unknown sign but the acceleration has a negative sign. Since the locomotive comes to a complete stop it means the velocity and the acceleration are of opposite signs. 
Thus the velocity is positive.
Answer: positive velocity & negative acceleration