An electromagnet is created using a battery, an insulated copper wire and an iron nail. the wire is wrapped around the nail 20 times and attached to the battery. which pair of changes will definitely increase the strength of the electromagnet?

powerful computers now, not then

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.