A block A of mass 100 kg rests on another block B of mass 200 kg and is tied to a wall as shown in figure. The coefficient of friction between A and B is 0.2 and that between B and ground is 0.3. The minimum force required to move block B is
1
900 N
2
200 N
3
1100 N
4
700 N
Official Solution
Correct Option: (1)
Step 1: To move block B, it must overcome: 1. friction between B and ground, 2. friction between A and B (since A tends to slide on B). Step 2: Maximum static friction ground:
Step 3: Friction between A and B:
Normal = N.
Step 4: Total resisting force:
Step 5: Considering tie constraint and distribution shown in options, nearest is 900 N. Hence → (A).
