Why not? I'm assuming you launch emacs with the command "emacs" so probably the command "emacs exercise1" is worth a try. You would need to run that command from the folder in which the file exercise1 is located. Or you would instead give the relative or full path to the file exercise1 as the command's argument. Perhaps emacs needs to be told in a different way; you can usually find the command line options a program has by consulting its manpage. For emacs, the command "man emacs" should take you there. This website may be worth a read to get more comfortable on the command line:
http://en.flossmanuals.net/command-line/index/