A wedge of inclination `theta ` is placed on a smooth surface. Ablock of mass m placed on the wedge is found to be stationary w.r.t the wedge . Select the correct alternative .

Options

A. If the wedge is accelerating in -x direction the wedge surface must be rough
B. If the wedge is accelerating in x-y plane in a direction making angle `alpha` with the x - direction where `0 lt alpha lt (pi)/2 - theta` , the wedge may be smooth
C. Wedge may be accelerating along - y - direction . In this case, it may be smooth .
D. Wedge may be accelerating along z - direction . In this case, it must be rough enough

Answer

B, D