Answer:
If iron, nickle, or cobalt is an answer choice, those are the three metals that are purely magnetic.
If he is jumping you are adding force which means that you will be falling twice as fast
B. A hypothesis is just an idea. And can become a Theory if there is some evidence. However a Theory is not a law, but an idea with supportive evidence
The air pressure inside the balloon increases as the number of particles increases.
If you wrap some of the wire around the nail in one direction and some of the wire in the other direction, the magnetic fields from the different sections fight each other and cancel out, reducing the strength of your magnet.
