Spring acting on an object (dynamics)

[flyingpig]

Why do ideal springs stop at xf = 0? We have friction in this problem, does that mean it really doesn't stop at xf = 0, but xf < 0?

 

[flyingpig]

Femme you have a lot of interesting physics problems. I want your book lol

 

[I like Serena]

Why do ideal springs stop at xf = 0? We have friction in this problem, does that mean it really doesn't stop at xf = 0, but xf < 0?

Yes, you're right. :)
If the block is stopped by friction before xf = 0, then we will have xf < 0.
That's what you get for things not being ideal (since the problem is not "frictionless")! ;)

 

[flyingpig]

Is that also true for vertical springs?