HELPP Viewed from Earth, it seems as if the Sun moves across the sky each day. This is because:
A. the sun isn't moving; observations made from Earth are rotating with the Earth
B. the Earth goes around the Sun over the course of a year
C. the Sun revolves around the Earth
D. the Earth isn't moving

Ithink it’s: light bounce if off a mirror

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.

You need to calculate the string in between two masses