A block of mass M is supported by a cord C from a rigid support, and another cord D is attached to the bottom of the block. If D is given a sudden jerk D breaks But if D is pulled steadily, cord C breaks. Why ?

Explanation

To understand why cord D breaks when given a sudden jerk, while cord C breaks when D is pulled steadily, we can analyze the forces acting on the block and the cords in both scenarios.

### Step-by-Step Solution:

1. **Identify the Forces Acting on the Block:**
- The block of mass M is subjected to two forces: the gravitational force acting downward (Mg) and the tension in cord C acting upward (T_C).
- When cord D is attached to the bottom of the block, it also exerts a tension (T_D) on the block.

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