Applied horizontal force homework

[shakabra]

Homework Statement

Two veggieburger patties, in contact with each other, are being pushed across a grill. The masses of the burgers are 113 g and 139 g. Friction is negligible. The applied horizontal force of magnitude 5.38x10^-2 N is exerted on the more massiv burger. Determine
a) the magnitude of the acceleration of the two-burger system, and
b) the magnitude of the force exerted by each of the two burgers on the other.

Homework Equations

F=ma
Fnet = Fapp -Ff
Fn=Fg

The Attempt at a Solution

Honestly, I have no idea how to solve this question. I tried subtracting the applied horizontal force of magnitude from the force of gravity and multiplying the result by .139 kg. I then divided it by the total mass. However, that didn't give me the right answer, so I assume I am wrong. Any hints would be greatly appreciated.

 

[shakabra]

The answers are:
a) .213 m/s^2
b) 2.41 x 10^-2 N

Once again, any help would be quite beneficial! :)

 

[alphysicist]

Hi shakabra,

The starting point for these problems is almost always the same: draw a force diagram, showing all forces. What do you get? Based on your force diagram, why is your procedure from your first post (subtracting the applied force from the force of gravity) not right?

What equation do you get from your force diagrams?

 

[shakabra]

Thank you for replying, but I think I already got the answer.
For part a) I used the F=ma formula and rearranged it, added the weights and added the known values into the equation. For part b) I used the same equation as part a) using acceleration from part a) and then to find the total force I did the force subtraction.
Once again, thank you for taking the time to reply to my question. It is greatly appreciated. :)