A $2100-$lbf rear$-$wheel drive tractor carrying $850$ lbf of gravel starts from rest and accelerates forward at $1\mathrm{.}87f\frac{t}{s^2}.$ Please note that for rear$-$wheel drive vehicles, static friction is applied only to the rear wheels.

Determine the reaction at each of the two rear wheels $A.F_A=$ i $+($bbf$)$

Determine the reaction at each of the two front wheels $B.F_B$ i $+$ j $($lbf$)$