How long does it take a packet of length 1000 bytes to propagate over a link of distance 2500 km, propagation speed 2.5 times 10^8 m/s, and transmission rate 2 mbps more generally, how long does it take a packet of length l to propagate over a link of distance d, propagation speed s, and transmission rate r bps? does this delay depend on packet length? does this delay depend on transmission rate?

Why were most movies from the late 1890s until the early 1930s only filmed in black and white? there were only a few people who could afford the technology to produce color motion pictures back then. audiences did not want color motion pictures until later. the film used to make color motion pictures often overheated, which was a safety hazard, so it was generally not allowed. color films had to be hand-colored, frame by frame.