Consider the arrangement illustrated in the figure. Suppose a small electric field E acts in the vertically upward direction, and the upper block has a positive charge Q on its top surface. The friction coefficient between the two blocks is , while the floor is smooth. Determine the maximum horizontal force F that can be applied without disturbing the equilibrium. [Hint: The force exerted on a charge Q by the electri

Step-by-step solution

Let N be the normal reaction between the upper block of mass m and the lower block of mass M . For the upper block, the forces in the vertical direction are its weight mg acting downwards, the normal reaction N acting upwards, and the electric force F_e = QE acting upwards (since the charge is positive and the electric field is vertically upward). For vertical equilibrium of the upper block: N + QE = mg N = mg - QE The maximum static friction force between the two blocks is: f_ = N = (mg - QE) Let T be the tension