Stick slip friction, spring force.

[MaxManus]

Homework Statement

The block has mass m. A spring (with spring constant k and equilibrium length b) is
attached to the block at the point x. The free end
of the spring is at the point xb. We move the free end of the spring with a constant
velocity u. The static and dynamic coefficients of friction for the contact between the
block and the bottom surface are μs and μd respectively. The acceleration of gravity
is g = 9.8m/s2.
The block starts at the position x(t0) = 0 at the time t0 = 0. The position xb of the
free end of the spring is xb(t0) = x(t0) + b at t0.

If the block starts at rest, what is the extension \Deltaxc = (\Deltaxb − \Deltax) of the spring when
the block starts moving?

 

[tiny-tim]

Hi MaxManus!

(is the spring vertical? )

Show us what you've tried, and where you're stuck, and then we'll know how to help!

 

[MaxManus]

Thanks for answering
No, the spring is horizontal.





I must admit that I don't have anything to show I don't know how to attack the problem other than, which was given in the exercise.

F = k(xb -x -b)i