# Homework Help: Force pushes and pulls two blocks at an angle

1. Sep 24, 2010

### gap0063

1. The problem statement, all variables and given/known data
A force of 23.52 N pushes and pulls to blocks
as shown in the figure below. The vertical
contact surfaces between the two blocks are
frictionless. The contact between the blocks
and the horizontal surface has a coefficient of
friction of 0.29.
The acceleration of gravity is 9.8 m/s2
What is the magnitude a of the acceleration
of the blocks?

2. Relevant equations
I know its the sum of Fy=N-mg=0 => N=mg
and the sum of Fx= -fk=max

3. The attempt at a solution
fk=ukN=> fk=20.4624
but I do not know how to plug in Fcostheta or Fsintheta and I know those need to be used somewhere

[PLAIN]http://img685.imageshack.us/img685/9849/006sl.png [Broken]

Last edited by a moderator: May 4, 2017
2. Sep 24, 2010

### jhae2.718

Create a free body diagram for each block, and then use ∑F=manet to find the resulting acceleration.

What forces are acting on each block?
How can you use these forces to find the net force on the blocks in the x direction?

3. Sep 24, 2010

### gap0063

On the first block in the y direction there is N and m1g
in the x direction there is fk and F...
On the second block in the y direction there is Fsintheta, N, and m2g
in the x direction there is fk and Fcostheta...

right?

4. Sep 24, 2010

### Staff: Mentor

The sum of the vertical components on each block must add to zero, but N and mg are not necessarily the only forces with vertical components.
The sum of horizontal forces must equal max. What are the horizontal forces acting on this system?

5. Sep 24, 2010

### gap0063

Thanks! figured out the other components!!!

Thank you for you're help on my other problems too you're a live saver