IS this all on one ticket or have you self booked and it's on two? The former and you'll be rebooked onto the next available flight the latter you'll be springing out for new ones.

Which airline is this?

As Analise says you need to subtract off their doors close time from the 50 minutes so you'll be closer to 30 minutes.

As you are arriving from a non schengen country and flying to a schengen one you need to clear immigration at CPH. You'll also have to do a security check.

here is some info on the CPH website about transitting.