A uniform cube of mass m and side a is placed on a frictionless horizontal surface. A vertical force F is applied to the edge as shown in Fig. 7.8. Match the following (most appropriate choice):
(a) mg/4 <F <mg /2 (i) Cube will move up.
(b) F > mg/2 (ii) Cube will not exhibit motion.
(c) F > mg (iii) Cube will begin to rotate and slip at A.
(d) F = mg/4 (iv) Normal reaction effectively at a/3 from A, no motion.