The rear side of a truck is open and a box of 40 kg mass is placed 5 m away from the open end as shown in figure. The coefficient of friction between the box the surface below it is 0.15. On a straight road, the truck starts from rest and accelerates with 2 ms^-2 . At what distance from the starting point does the box fall from the truck? (Ignore the size of the box.)

• A

  20m

• B

  10m

• C

  $\sqrt{20}\mathrm{m}$

• D

  5m