I've seen the following sentences in a book.
The brake shoes are worn out.
The tires are worn.
I'm wondering when to use "worn" and when to use "worn out".
Worn: a worn object is old and damaged, especially because it has been used a lot
Worn out: too old or damaged to be used
It seems that "worn out" and "worn" have the same meaning. Do I need to be careful when using "worn out" and "worn"?