True, the path of the ball, as observed from the train window, will be a horizontal straight line.
An object projected from a certain height has a parabolic path when observed from a fixed point. 
However, if the reference point is moving at the same velocity as the object, the path of the object's motion appears to be a straight line.
When the ball is released from the window of the train, it will move at the same constant velocity as the train, and the path of the ball's motion observed from the train window will be a straight line.
Thus, we can conclude that the given statement is true. The path of the ball, as observed from the train window, will be a horizontal straight line.
Learn more about path of motion of objects here: brainly.com/question/82610
 
        
             
        
        
        
Answer: C. Africa 
Explanation:
The data given on the graph shows that:
Asia will grow from around 1,300 million to 5,000 million in 2050 which is an increase of:
= 5,000 /1,300 = 3.84 times
Europe will decrease over that period. 
Africa will go from around 300 million to 2,000 million which is an increase of:
= 2,000 / 300
= 6.67 times 
Mexico
, Central America, Caribbean Islands:
= 900 / 120
= 7.5 times
United States,  Canada, and Greenland:
= 400/120
= 3.33
Oceania:
= 50 / 13
= 3.85
From the options give, Africa will see the greatest increase at 6.67 times its population in 1950.
 
        
                    
             
        
        
        
As you move across a period, the atomic mass increases because the atomic number also increases. When the atomic number increases, this means that there are more protons and neutrons that add to the atomic mass of an atom
        
             
        
        
        
Distance and force.
You need to know how much force was needed and how far it went to calculate how much work was done. The answer is C.
        
                    
             
        
        
        
Answer:
a
   
b
   
Explanation:
From the question we are told that 
    The inner radius is 
    The  outer radius is  
     The nu umber of turns is  
     The current it is carrying is  
Generally the magnetic field is mathematically represented as 
       
Where   is the permeability of free space with a constant value
 is the permeability of free space with a constant value    
             
And the given distance where the magnetic field is felt is  r =  0.9 cm  =  0.009 m 
Now  substituting values 
      
     
     Fro the second question the distance of the position considered from the center is  r =  1.2 cm  =  0.012 m 
So the  magnetic field is  
         
         