Answer:The most important process would be the ice crystal process 
Explanation:
Ice crystal process also called Bergeron process requires numerous small water drops that are supercooled, which is a common feature in clouds between about 0° and -20°C or below, along with a small number of ice crystals. Therefore because the collision-coalescence process requires that cloud droplets be of varying size so that drops will fill at different speeds, the most important process would be the ice crystal process.
 
        
             
        
        
        
Answer:

Explanation:
consider the mass of each train car be m
m₁ = m₂ = m₃ = m
speed of the three identical train
u₁ = u₂ = u₃ = 1.8 m/s
m₄ = m             u₄ = 4.5 m/s
m₅ = m              u₅ = 0 (initial velocity )
final velocity 
v₁ = v₂ = v₃ = v₄ = v₅ = v
using conservation of momentum
m₁u₁ + m₂u₂ + m₃u₃ + m₄u₄ + m₅u₅ = m₁v₁ + m₂v₂ + m₃v₃ + m₄v₄ + m₅v₅
m (1.8 + 1.8 + 1.8 +4.5) = 5 m v


 
        
             
        
        
        
Around 27 satelites is used for GPS technology
        
                    
             
        
        
        
And.. where is the rest of the question?
        
             
        
        
        
Answer:
3.43 m/s^2
Explanation:
Force is equal to mass times acceleration. (F=ma). You can use inverse operations to get the formula for acceleration, which is acceleration is equal to force divided by mass. (a=F/m). Since there are two forces here, the force friction (55 N), and the force applied (175 N), we must solve for the net force. To solve for the net force, you take the applied force (175 N) and subtract the frictional force from it (55 N). Thus, the net force is 120 N. With this done, we can now solve for our acceleration. 
Using the equation for acceleration, we take the force and divide it by mass.
120/35
Answer: 3.43* m/s^2**
*Note: This is rounded to the nearest hundredth, the full answer is: 3.42857143
**Note: In case you're confused, this is meters per second squared.