a grind stone that rotates 2000 rev/min requires 50s to come to a stop. find the angular acceleration of the grind stone. how many radians does it turn through before stopping.​

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.

Electric force between two charged object varies inversely as the square of distance between them (coulomb's law). this means if two charged objects move away force between them decreases.