8. semiconductors

a) do not obey ohm's law
b) obey ohm's law
c) do not use electrons to conduct electricity.
d) need light to work

Suppose you use a machine that gives you a mechanical advantage of 2 to achieve an output force of 30newtons what must the input force be

Which configuration would produce an electric current? a) rotate a coil of copper wire between two magnets. b) connect a wire between a copper and zinc strip sitting in a beaker of water. c) connect a wire to the (+) positive end of a battery and the other end to a light bulb. d) connect a wire to the negative end of a battery and the other end to a light bulb.

If steel is more dense that lake water, why can a boat float