My friends and I were building a physics project--making a galvanometer which can be used to measure current. We wrapped a nail with copper wire and then connected the two ends of copper wire to a 1.5v battery. But something weird happened: the solenoid we made could only attract to permanent magnets. It couldn't repel the magnets at either ends. Can somebody help us out ? We desperately need some advice :D3 個解答Physics1 0 年前
片頭語錄:No one would have believed in the early years
of the twenty-first century that our world was being watched
by intelligences greater than our own. That as men busied
themselves about their various concerns, they observed - and
studied. With infinite complacency, men went to and fro about
the globe, confident of their empire over this world. Yet, across
the gulf of space, intellects vast, and cool, and unsympathetic
regarded our planet with envious eyes... and slowly, and surely,
drew their plans against us.
片尾: From the moment the invaders arrived, breathed our air, ate, and drank, they were doomed. They were undone, destroyed, after all of man\'s weapons and devices had failed, by the tiniest creatures that God and his wisdom put upon this earth. By the toll of a billion deaths, man had earned his immunity, his right to survive among this planet\'s infinite organisms. And that right is ours against all challenges. For neither do men live nor die in vain.
(是誰配音的?)2 個解答電影1 0 年前