Paper is sold in packets labelled 80g/m². This means that a sheet of paper of area 10000 cm as a mass of 80g
The thickness of each sheet is 0.11mm.
What is the density of the paper?

In this thread, i would like you to comment on the nature of light and how operation of telescopes. light has a duality of a particle and a wave; which one affects your life? also how does light interact with optics inside telescopic systems? answer these questions in two paragraphs. then respond the another students response.