Question 3 of 10 Jake lifts a backpack with a force of 30 N to a height of 1 meter in 4 seconds.
How much work does he do on the backpack?
A. 120 N
B. 30 N
C. 15 N
D. 60 N

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.