2.5 and better. It various, depending on brand and design. The different manufacturers are constantly improving the glide-ratio for their suits.
Lift/Drag x Height loss
To calculate the glide ratio, you divide the length it was thrown, e.g. 150cm, by the height it was thrown, e.g. 50cm. So 150/50=30cm so, it would be 30:1.
133 to 140 knots
In an md80 id say around an hour
That would be a function of the glide ratio of the paper airplane in question.
The max speed of an MD80 is 500kt, cruising speed around 440kt.
Around 30 to 172 passengers depending on variant and seating configuration.
The 747 has about a 17 to 1 glide ratio. If we figure a cruise altitude of 42,000 ft. (8 miles). Then a 747 in cruise could glide 136 miles. Assuming that the landing area is at sea level. Even if cruise alt is a bit lower, its reasonable to say a large commercial airliner at cruise altitude can glide somewhere around 100 miles.
A glide refletion is a glide that has reflection.
Yes. A 747 has a glide ratio of approximately 15:1. It can glide about 15 miles for every 1 mile it decends. British Airways found this out when their flight 9 lost all 4 engines due to volcanic ash near Jakarta, Indonesia 24 June, 1982.
The combination of wing area and plane weight affect a paper airplane's glide ratio and range.