The momentum of a 3000 kg truck is 6.36 x 104 kg·m/s. At what speed is the truck traveling? m/s 472
19,080
2.1
21.2
19.6
24.5

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.