Answer:
Explanation:
When a camera shifts focus from a faraway object to a nearby object, the lens-to-film distance must increase. Likewise, when it shifts focus from a nearby object to a distant object, there must be an increase in the lens to film distance (that is, the image distance). 
Therefore, if the picture of an object that is far away, the lens must move towards the film. 
The focal length cannot be changed because it is fixed for a lens. Nevertheless, in order to focus on an object, the image distance can be changed.
 
        
             
        
        
        
You get a more low sound.  
Conversely, when the wavelength becomes shorter you get a more treble sound.
;-)
 
        
                    
             
        
        
        
Answer: C
Explanation: As the universe stretches it expands more and more the distance between each other. Hope this helps. 
 
        
                    
             
        
        
        
Answer:  20 m/s 
Explanation: 
P = mv 
since we're trying to find the velocity, you change the formula to v = P/m
v = ?
P = 9 kgm/s 
m = 0.45 kg 
v = 9 kgm/s / 0.45kg  = 20 m/s