What causes earth's magnetic field to flip?

The generation of Earth's magnetic field starts at its very center. Some researchers believe polarity reversals are caused by a disturbance in the balance between Earth's rotation and the temperature at the core, which alters the fluid motion of the liquid iron, but the exact process remains a mystery.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."