Answer:
What goes through a door but never goes in and never comes out?
I fly when I'm on and float coming off.
When I get closer my tail grows longer but when I go away my tail leads the way.
The Titanic is still here.
Soft and cuddly I'll pull on your heart. But take my last name and I'll tear you apart.
I am used for light yet I am solid. Without me you would feel enclosed. I hate being touched especially with a lot of force. I like to be in buildings.