A block of mass 0.4 kg rests on the inclined surface of a wedge of mass 1.7 kg. The wedge is acted upon by a horizontal force F~ and slides on a frictionless surface. The acceleration of gravity is 9.81 m/s2.

If the coeﬃcient of static friction between the wedge and the block is 0.9 and the angle of the incline is 31◦, ﬁnd the minimum value of F~ for which the block does not slip. Answer in units of N

~ is the vector sign