A bullet train traveling at 2.5m/s, takes 30 minutes to get to the station. What was the train's acceleration in m/s^2?

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

Which two particles are found in the center of an atom

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.