From the information you have observed, determine the following:
What rule of magnetism is illustrated by the lines of the iron filings in Step 12?
What rule of magnetism is illustrated by the lines of the iron filings in Step 15?
Why was glass or plastic used to separate the filings from the magnets in the experiments?
Did the glass or plastic stop the passage of the magnetic lines of force?
Did the iron filings almost or completely bridge the open end of the horseshoe magnet?

. west

the answer is f1 and d2 because if you put equal force on those two points the beam would balance trust me on this

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me

305.7

explanation:

density =m/v

density =917/3.00

density = 305.

approximately = 305.7

in four significant figures