Gabriel used an iron nail to build an electromagnet (like the one seen below) that will pick up 4 paper clips. He has tried many changes to increase the strength of his electromagnet so that it will pick up 10 paper clips? For each of the following changes, predict and explain the most likely outcome for 2 points each:

Replacing the iron bolt with a plastic rod
Increasing the number of coils in the copper wire
Increasing the size of the battery

pretty sure it's false

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me