Re: usb disc is write protected
The output of dmesg would help here, but it looks like your stick is being mounted read-only. This could be due to one of two factors:
1. Somehow Ubuntu is set up incorrectly to mount it as read-only instead of the default read-write (unlikely)
2. There is filesystem damage on the stick (most likely)
How are you trying to format it? Have you tried using Gparted to format it, as this won't require it to be mounted?
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.