FORT LAUDERDALE, Fla. — A new shark-repellent device demonstrated in a viral YouTube video is drawing attention for what appears to be its ability to drive away dozens of sharks with a single blast.
Engineeringness on MSN

Why do magnets attract and repel

Magnets can pull objects closer or push them away without even touching. This video explains why magnets attract and repel, and how magnetic poles and fields make this possible. A simple and clear ...