Why is it difficult to construct a practical calendar based on the moon’s cycle of phases?

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.

How many times did thomas edison mess up the light bulb

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter