Equilibrium help!

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Hi, I'm having slight problems with the following equilibrium question and was wondering if anyone could help me out? I'm not really good at visualizing these situations so help is very much appreciated!

Question:

A block of mass m is lying on a rough table, the coefficient of friction being µ. One end of an elastic string is attached to the block. The other end of the string is pulled in a direction away from the block so that the string is at an angle of 45° to the horizontal.

What would that look like in a diagram with the forces acting on the block and table? Rolling Eyes

Thanks for taking time to read this post.

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* A force of g*m downwards from gravity. (vertical)

* A force of ? at an angle of 45° to the horizontal from the elastic string. (why elastic?)

It can be drawn as two forces equal to ?*cos(45) horisontal and ?*sin(45) vertical (uppwards i presume).

* A force uppwards from the table surface equal to g*m - ?*sin(45)

(canceling what force from gravity has not been cancelled by the vertical component of the force from the string.)

* A force in the opposite direction of the horisontal component of the elastic band due to friction. (horisontal in the opposite direction)

This force will be equal to ?*sin(45) if the block isn't accelerating.

(it has to exactly cancel the horizontal component of the string pull, or the block would accelerate)

It will also be equal to µ*(g*m - ?*sin(45)) if the block is moving.

(µ*(vertical force from table) )

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Equilibrium help!

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