physics
posted by Jud .
a 1.50 kg book is sliding along a rough horizontal surface. At point A it is moving at 3.21 m/s, and at point B it has slowed to 1.25m/s.
1.) How much work was done on the book between A and B?
2.) If 0.750 J of work is done on the book from B to C, how fast is it moving at point C?
3.) How fast would it be moving at C if +0.750 J of work were done on it from B to C?
4.) The book slides a distance of 2.50m from A to B. Determine the coefficient from A to B whilst using constantforce work formula to recalculate the answer to #1.)
I'm having real trouble with this problem.

Horizontal surface, no change in PE.
a) work done is by friction...what is the difference in KE
b) same principle
c) same principle
4) friction=work/distance
mu*mg=work/distance solve for mu 
Ok. Thanks! Now I can have my starting point. Thank you.

a jogger run around a square city block with sides of 30m. if she start an end at point a what distance has she run