Answer:
The deceleration of the plane is 0.25 m/ .
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Explanation:
Deceleration is the converse of acceleration.
From first law of motion, we have;
v = u + at
where: v is the final velocity, u is the initial velocity, a is the acceleration and t is the time taken.
Thus,
v = 50 m/s
u = 80 m/s
t = 120 s
50 = 80 + 120a
50 - 80 = 120a
-30 = 120a
a = 
   = -0.25
a = -0.25 m/
The deceleration of the plane is 0.25 m/ .
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Answer:
Paleontologists study fossils so that we can understand the evolution's from past species to the current ones. It also opens a window to discovering exactly how long earth has been around by finding out the age of the fossil itself. Though paleontology has been in the decline recently, and i'm sure we haven't found out all we need to know from these fossils. 
Explanation:
 
        
             
        
        
        
The basic building blocks of matter are called atoms.
        
                    
             
        
        
        
Isolation can be due to behavioral, geographical, or temporal barriers. <span>Speciation can take place in two general ways. A single species may change over time into a new form that is different enough to be considered a new species. This process is known as anagenesis. More commonly, a species may become split into two groups that no longer share the same gene pool. This process is known as cladogenesis. There are several ways in which anagenesis and cladogenesis may take place. In all cases, reproductive isolation occurs. Hope this helps! </span>