If a 56k modem downloads a maximum of 56000 bits per second how long does it take to download a 4mb file? (please show workings as I am interested to see the calculations.)
Back in the days when I had a 56k connection (2000/01), the fastest speeds I could hope for were arouns 44/45k on BTInternet which was a little better than the 39/40k I was getting on Freeserve.
Download speeds off that were typically four or five Kb/second which basically means rather a long time for a 4Mb file!
The theoretical throughput is 57344 bits per second (1024 bits in a kilobit). 8 bits to a byte. 1024 bytes to a kilobyte. 1024 kilobytes to the megabyte. This makes 4*8*1024*1024 (33554432) bits in a 4Mb file. Therefore, 585.14285714285714285714285714286 seconds to download.
IP and TCP packet headers make up some of the data, so this will slow it down too.
Obonio is spot on. Although it does depend on network conditions... You may notice that yr connection is faster or slower depending on the time of day. Nightime is usually faster coz not many people are on line.