Answer:
  The velocity of a falling object
Explanation:
   The positive X axis is towards right and positive Y axis is towards up, so North direction is positive
   A vector with less than 1 magnitude is not negative, because its magnitude may be in between 0 and 1 which is positive vector.
   Any vector whose magnitude is greater than 1 is never be a negative vector.
   The velocity of a falling object is towards bottom, that is towards negative Y axis. So that vector is negative.
 
        
             
        
        
        
Answer:
Period
Explanation:
we know that
The period of a wave is the time required for one complete cycle of the wave to pass by a point. 
 
        
                    
             
        
        
        
velocity = traveled distance ÷ time of the traveled distance is seconds
velocity = 600 ÷ 60
velocity = 10 m/s
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Kinetic Energy = 1/2 × mass × ( velocity )^2
KE = 1/2 × 60 × ( 10 )^2 
KE = 30 × 100
KE = 3000 j