1. The problem statement, all variables and given/known data http://imgur.com/a/vA0H2 2. Relevant equations $$F=ma$$ $$r \times F = I \alpha $$ 3. The attempt at a solution Denoting the forces at the back wheel with a 1 and front wheel with a 2 and calculating the torques around the CoM I have $$F-f_1-f_2 = mA$$ $$N_1 + N_2 -mg = 0$$ $$hf_1 + h_f2 - hF +bN_1-aN_2=0$$ with $$f_i = \mu_i N_i$$ So just using this I can't seem to solve for A in terms of mu and g. I have some questions though, is mu the same for both wheels? The also mentions "rolling without slipping", am I meant I incorporate this somehow?, it doesn't give any explicit info and moments of inertias of the wheels so I don't see how. Any help would be appreciated.