Which property of matter changes during a chemical change but does NOT change during a physical change? Which property explains why copper often is used in electrical wiring?

Which graph best represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator?

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.

Achild has maximum walking speed of 1.6 m/s. what is the length of the child's legs? 0.26 m