Answer:B.As the north pole of the electromagnet nears the south pole of the permanent magnet, the current reverses and the poles of the magnets then repel.
Explanation:
 
        
                    
             
        
        
        
Answer:
The answer is D.  A Vacumn
Explanation:
Sound cannot travel through a vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work in.
 
        
             
        
        
        
Answer:
70.5 mph
Explanation:
A passenger jet travels from Los Angeles to Bombay, India, in 22h.
The return flight takes 17 h.
The difference in flight times is caused by winds over the Pacific Ocean that
blow primarily from west to east.
If the jet's average speed in still air is 550 mi/h what is the average speed
of the wind during the round trip flight? Round to the nearest mile per hour.
Is your answer reasonable?
:
Let w = speed of the wind
:
Write a distance equation (dist is the same both ways
17(550+w) = 22(550-w)
9350 + 17w = 12100 - 22w
17w + 22w = 12100 - 9350
39w = 2750
W = 2750/39
w = 70.5 mph seems very reasonable
:
Confirming if the solution by finding the distances using these value
17(550+70.5) = 10549 mi
22(550-70.5) = 10549 mi; confirms our solution of w = 70.5 mph
 
        
             
        
        
        
A because the toaster converts electrical energy into heat energy and, after the bread has been heated for sufficient time, toasts pop out, ready to be buttered. And converting means transforming.