I FINALLY GOT THE RIGHT ANSWER! unfortunately I have no idea why it's right. If somebody could please explain it to me. So what I did to get the right answer was set up a free body diagram for the top box first, with the force pushing to the right (P) and friction pushing to the left (-Ff) and...
First of all thanks for responding, I had given up on this problem. So If I plug in 4 instead of 16, like you suggest P comes out to 47.04 N, which is also wrong.
This leads me to suggest that you do NOT use 5.88m/s^2 for the acceleration. (the acceleration from part a). I have two more...
1. A block of mass m2 = 4.00 kg block is placed on top of another block of mass m1 = 12.0 kg block that rests on a frictionless, horizontal table. The coefficient of static friction between the two blocks is 0.600.
http://www.flickr.com/photos/43001762@N07/3963579065/
(a) What is the maximum...