# Box problems

1. Nov 15, 2012

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

--F-->{3.9kg}{5.8kg}{8.3kg}

Three blocks are in contact with each other
on a frictionless horizontal surface. A 413 N
horizontal force is applied to the block with
mass of 3.9 kg as shown in the figure below.
The acceleration of gravity is 9.8 m/s2 .

d)What is the magnitude of the force between
the block with mass 5.8 kg and 8.3 kg?

e)What is the magnitude of the force between
the block with mass 3.9 kg and 5.8 kg?

2. Relevant equations
F=ma
F=9.8m/s^2(m1+m2)

Not quite sure, I have been trying to work with these two but am not having much luck.

3. The attempt at a solution

I am hopelessly lost on this one. My teacher is extremely difficult to understand and physics is really giving me a tough time. Any help would be greatly appreciated! Thanks in advance.
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Nov 16, 2012

### lewando

I your teacher is hard to understand or worse--not a good teacher, you will have to do some independent study to stay afloat. Read your textbook slowly and thoroughly. Work with a classmate if possible. Use this site's learning materials. Find and use internet resources.

What is the acceleration of the group of blocks?
Since there is no friction and these blocks are moving horizontally, the acceleration due to gravity is not relevant.
Can you draw free body diagrams of the individual blocks? If you can, then you are almost done.

3. Nov 16, 2012

### Basic_Physics

All the blocks are moving together, like a train, under the influence of the horizontal force.
Using Newton's 2nd law, what are their acceleration?