Answer:
a)At the mean position
b)At the extremes positions
Explanation:
Given that mass is having oscillation motion.
We know that
1. At the mean position -The velocity of the mass is maximum and the acceleration of the mass is minimum.The net force on the mass will be zero.
2. At the extreme position-The velocity of the mass is minimum and the acceleration of the mass is maximum.The net force on the mass will not be zero.
Therefore 
a)At the mean position
b)At the extremes positions
 
        
             
        
        
        
Answer:
Microwaves fall in the range of the EM spectrum between radio and infrared light.
Explanation:
 
        
             
        
        
        
Answer:
4800
Explanation:
You have to multiply the 1200 kg and the 2 m/s2. Then multiply the other 2 by the 2400 because it was the answer to the first part now after you multiply your answer is 4800.