Arock exerts 5000 pa of pressure on the ground. if the rock weighs 250 n, how much area is in contact with the ground?
8 m2
50 m2
20 m2
0.05 m2

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.