1. The problem statement, all variables and given/known data A box of mass 11.3 kg rests on the flat bed of a truck; the box is not tied down in any way. The coefficients of friction between the box and the flat bed are mu_s = 0.19 and mu_k = 0.14. The truck stops at a stop sign and then starts to move with a carelessly large acceleration of 2.20 m/s^2. I found the force of friction first --- 15.5 N then i found the accel of the box --- 1.37 m/s^2 Now i am having trouble finding this next part. If the box is a distance 1.83 m from the rear of the truck when the truck starts, how much time elapses before the box falls off the truck? 2. Relevant equations f=ma vf2=vi2+2ad v=d/t 3. The attempt at a solution So for this last part this is what i did. vf22= 0 + 2(1.37)(1.83) vf= 2.24 t = 1.83/2.24 t= 0.817 seconds this was wrong so i thought oh well the truck is accelerating right and the box is accelerating in the opposite direction so i took a new approach. vf22= 0 + 2(2.2-1.37)(1.83) vf= 1.74 t = 1.83/1.74 t= 1.05 seconds but to no avail. this was wrong also so i thought again well the truck is accelerating right and the box is accelerating left so maybe i use total acceleration vf22= 0 + 2(2.2+1.37)(1.83) vf= 3.61 t = 1.83/3.61 t= 0.507 seconds wrong as well :( i dont know what else to try. what am i doing wrong?