A 3.0 kg and a 5.0 kg box rest side by side on a smooth, level floor. A horizontal force of 32 N is applied to the 3.0 kg box pushing it against the 5.0 kg box, and, as a result, both boxes slide along the floor. How large is the contact force between the two boxes?
a) 32N b)24N c) 0N d)20N e) 12N
The Attempt at a Solution
I found the total mass which is 8kg. And then using the F=ma equation, I found my acceleration which is 4 m/s^2. And now...I'm completely stuck on what to do. In class we weren't given an example like this, so I don't know where to go from here...