Running 2 apps on 1 linode

I have a rails app running on a linode. Now I have another Rails application I want to deploy. I haver a couple of newbie questions I hope someone can help me with:

I'm debating if I should purchase a new linode or add it to my existing Linode?

Can I easily run two apps side by side on one linode?

What are the steps to do this?

Do I simply create a new disk image and set up that domain to point to the Linode IP address. Do I have to get another IP address or can it be the same?

What is the necessary RAM / storage that is typically needed to do this?

Sorry for my newbies questions, but I really like to hear the experiences from people here on the forum regarding this.

Thanks!