SIR,please tell me where i got wrong-a small force F is applied sothat the small box,boy C and the big box move together with anacceleration a.the coefficient of friction between the boxes is u andbetween the box and the road is 0.the boy D is standing on road.sir wehave to find the direction of frictional force.FOR BOY C(who is in non-inertial frame)-we have to apply a pseudoforce towards left but he box A is at rest w.r.t BOY C so thedirection of frictional force is towards right.FOR BOY D-the frictional force is also towards right.NOW the QUESTIONwhich came to mind is that for BOY D the friction is creating motionbut for BOY C the friction is not creation any motion(so he willconclude that friction always opposes motion).SIR,please tell me wherei got wrong.

manoj singh , 9 Years ago

Grade 10