1. The problem statement, all variables and given/known data http://img219.imageshack.us/img219/4953/physicsyo5.png [Broken] That's the best that I can do. As you can see, the two blocks are touching and both share the same coefficient of friction. There's an applied force on the first, lighter block. I've done all of my homework but just can't figure out: -Force exerted by the 80kg block on the 210kg block -Force exerted by the 210kg block on the 80kg block -I have already determined the net acceleration, which I believe is 1.410m/s^2 2. Relevant equations F=ma Ff=(Fn)(mu) 3. The attempt at a solution F=ma Fnet=(m)(anet) Fnet=(210kg)(1.410)=296.1N F=Fa-Fnet F=750-296.1=453.9N I believe this is the answer for the "Force of the 80kg block on the 210kg block". However, I don't know how to calculate the other. Any help is appreciated!