Answer: 750 kgm/s
Explanation:
Mass of object = 25 kg
Speed by which object moves =30 m/s. Linear momentum of the object = ?
Since momentum refers to the quantity of motion of the moving object, 
Linear momentum = Mass x Speed
= 25kg x 30m/s
= 750 kgm/s
Thus, the linear momentum of the object is 750 kgm/s
 
        
             
        
        
        
Average speed is worked out from dividing distance by time.
        
                    
             
        
        
        
1) 4min = 4*60 sec = 240 sec
2) Distance = speed times time = 3 * 240 = 720 m
        
             
        
        
        
Answer: For the first part the answer is Radio Waves and the second part’s answer is gamma ray.