Balance the equation-
Al+Mn02 ———-> Mn + Al2O3

Determine the amount of work done when a crane lifts a 100-n block form 2m above the ground to 6m above the ground

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.

How can you increase the strength of an electromagnet?