I am slightly confused about how to answer the following question:
"The diagram below shows a window-cleaning device that can be used to clean both sides of the glass at the same time. It consists of two plastic holders with bar magnets inside, and a cleaning material attached two the outside.
When the inner part of the device A is moved across the inside surface of the window, the outer part B follows it, moving over the outer surface of the window.
Explain why B follows the movement of A"
The answer to this question states:
"The opposite (N+S) poles are attracting one another and if (in picture) A is moved upwards its S pole will also resist the upward movement of B by repulsion. So B follows A."
I am a bit confused about this answer, isn't the inner part of the magnet A attracted to the outer part of magnet B? Why is it talking about repulsion, and how would that make the two magnets follow each other?