Streams carry sediment, like pebbles, in their flows. The pebbles can be in a variety of locations in the flow, depending on it's size, the balance between the upwards velocity on the pebble (drag and lift forces), and it's settling velocity.
        
             
        
        
        
        
Answer:
Bb can be an example
Explanation:
That is Because brown is dominated, so it is in Capital. 
 
        
             
        
        
        
Answer:Most likely yes, sorry if wrong!!
Explanation:
 
        
             
        
        
        
Answer:
487.23 N/m
Explanation:
Given:
mass of metal sphere 'm'= 0.51kg
the spring stretches from 0.12 m to 0.23 m. Therefore,
 = 0.12m and
= 0.12m and  = 0.23m
= 0.23m
the speed of the sphere decreases from 6.7 to 3.3 m/s. Therefore,
 = 6.7m/s and
= 6.7m/s and  =3.3m/s
=3.3m/s
In order to find spring constant, we apply law of conservation of energy. i.e
The change of the kinetic energy of sphere is equal to the change of potential energy of the spring.
So, Δ Δ
 Δ
where, 
Δ 1/2 m (
 1/2 m ( -
-  )²
)²
Δ = 1/2 k (
= 1/2 k ( -
 -  )²
)²
1/2 m ( -
-  )² = 1/2 k (
)² = 1/2 k ( -
-  )²
 )²
k= m [ ( -
-  )²/(
)²/( -
-  )²
 )²
k= 0.51 [(6.7-3.3)²/ (0.23-0.12)²]
k= 487.23 N/m 
Thus, the spring constant of the spring is 487.23 N/m