Magnetism is produced by the motion of electrons as they a. move around the nucleus. b. spin on their axes. c. both a and b d. none of the above

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )

d) physical means can be used to separate the components of air.

there are no components of a physical goal mentioned on the list of choices that you've provided.