It starts or speeds up.
Some substances need certain amount of energy in order to react with each other.
        
                    
             
        
        
        
Answer:
Explanation:
Given
radius of circular path  
 
Position is given by
 
 
Differentiate 1  to angular velocity we get
 
 
Differentiate 2 to get angular acceleration 
 
 
Net acceleration is the vector summation of tangential and centripetal force 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                    
 
        
             
        
        
        
Answer:
0.5mv^2=50, v=5, 25/2×m=50, m=50×2/25, So, the answer is 4
 
        
             
        
        
        
The property illustrated to each statement is commutative because it shows that for some value of t both statements are equal.