The attracting and repelling forces of magnets are used in countless objects, from refrigerator doors to maglev trains. Refrigerator doors use the attraction of magnets to stay closed, while maglev trains use magnetic repulsion to hover above rails. The center magnet in the picture is hovering between two magnets, making it appear to float. Which best explains how the center magnet is able to hover between two other magnets?
A) The opposite poles of each magnet are facing each other, so they repel.
B) The magnets are stacked so that similar poles are facing one another.
C) The middle magnet is repelling the top magnet while attracting the bottom.
D) The middle magnet is attracted to the top magnet, but held down by gravity.

Mass (kg) force (n) 5 25 10 50 15 75 20 100 a student was trying to find the relationship between mass and force. he placed four different masses on a table and pulled them using a spring scale. the table shows the different masses used in the experiment and the force required to pull each mass. the student concluded that more force was required to pull heavier objects. what comment would you make regarding his conclusion? a) no clear relation can be observed between mass and force from the data. b) there is a direct proportion between the mass and force listed in the table. c) gravity should have been taken into account while performing the experiment. d) there is an inverse proportion between the mass and force listed in the table.

Awave is produced in a rope. the wave has a speed of 33 m/s and a frequency of 22 hz. what wavelength is produced?

Light traveling in a medium with a refractive index 1.19 is incident on a plate of another medium with index of refraction 1.79. at what angle of incidence is the reflected light fully polarized?