When a bar magnet is broken into two pieces each piece has a north and south pole because

a
the magnetic fields reversed

b
every magnet is made of many aligned smaller magnets

с
bar magnets are permanent magnets

d
the magnetic poles have been isolated

If an astronaut takes an object to the moon the following is true (choose only one). a the mass will change but the weight will be the same. b both the mass and the weight of the object will be the same. c the weight will change but the mass will be the same. d both the mass and the weight of the object will change.

What sort of waves exhibit the doppler effect?

In the united states, tornadoes generally occur because of the freezing of ocean water underwater earthquakes meeting of cool and warm air masses shifting of warm and cool ocean currents