By conducting exhaustive, high-intensity online research for about 15 seconds, I found a source that says the speed of sound in copper is 4600 m/s.  (You could easily have completed the same research project in about 1/3 of the time it took you to type and post the question here.)
Time it takes = (distance) / (speed)
Time = (25,000 meters) / (4600 m/s)
Time = (25 / 4.6) km-sec/km
<em>Time = 5.43 seconds </em> 
 
        
             
        
        
        
An atom is the smallest unit of matter. It can't be broken. It consist of dense nuleus surrounded by negatively charged electrons.
        
             
        
        
        
It makes the data thet they collect more reliable so if they need the data again, they have already tested it a few times so therefor they know that it is right.
        
             
        
        
        
Efficiency =  Work Output / Work Input
92%  =  Work Output / 100
0.92 =   Work Output / 100
Work Output = 0.92 * 100
Work Output  = 92 joules.