On applying, ∑F=ma along horizontal. Nsinθ=ma .............(2) On applying, ∑F=ma along vertical. Ncosθ−mg=0 [ No vertical acceleration, a=0] Ncosθ=mg .............(3) On dividing equation (2) by (3). tanθ=ag ⇒a=gtanθ ⇒FM+m=gtanθ[ from (1) ] ∴F=g(M+m)tanθ Magnitude of F to keep block stationary with respect to wedge is F=g(M+m)tanθ