Physics
posted by CC on .
The coefficient for static friction for a 5 kg box on a floor is .72. How much force if required to start the box sliding?
I worked it as follows:
Force of friction=Force normal * coeffic. of friction which is .72*5*9.8=35.28 but answer in back of my book says this is wrong. Where did I err?

Force of Friction= Force of the normal*coeffic...
Coefficient= .72
Normal Force= mass*g
9.81*5
49.05
Solve: 49.05*0.72
35.316 or 35.32
Is that what you got? If it is, you're right. If not, recheck the book, it may be that you are looking at the wrong answer. 
Yes, that's my answer too. Incorrect answers at the back of the book drive me crazy! thanks for confirming!