A rollercoaster cart moves around a circular vertical loop of radius r at a speed higher than the minimum required to clear the loop at the top without slipping. What force, or forces are responsible for keeping the cart moving around the circle when it is at a height r above the bottom of the loop.

The field lines around one end of a bar magnet are shown below based on the diagram, what can you conclude about the pole of the magnet? a.is a south pole because the field hnes spread out from this end b.a north pole because the field lines spread out from this end c.a nouth pole because the field lines enter the magnet at this end d.is a north pole because the field lines enter the magnet at this end