# Finding the speed of a book against a vertical wall

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1. Sep 25, 2016

### Vanessa Avila

1. The problem statement, all variables and given/known data

the main question asks: "If the book is initially at rest, what is its speed after it has traveled 0.400 m up the wall?"
2. Relevant equations
∑F = m*a
vf2 = vi2 + 2 * a * d , when initial velocity is 0.
3. The attempt at a solution
So here's my free body diagram:

and out of that FBD I got these equations:
∑Fx=N−Fcos(60)=0
∑Fy=fk+Fsin(60)=ma

I know that fk=μ(Fcos(60)) = μN

Should i solve for the acceleration and then plug it in the kinematics equation to solve for final velocity? And are my equations and FBD right?

2. Sep 25, 2016

### cnh1995

The book is moving upward. Shouldn't the frictional force be downward then?

3. Sep 25, 2016

### Vanessa Avila

Oh okay so Fsin60 - mg - fk then? I forgot to add the mg on my equation up there.

4. Sep 25, 2016

### cnh1995

Right.

5. Sep 25, 2016

### Vanessa Avila

Ohh okay i didn't catch the "up" part on the question. So i can solve for acceleration now then given that equation?

6. Sep 25, 2016

### cnh1995

Yes. And then plug it in the kinematic equation

7. Sep 25, 2016

### Vanessa Avila

Awesome. I did that and i got the right answer. Thanks a lot! :)