Sir why sign gets winded when other block is stopped ,I feel the other mass will get moving by string and gets tightened

When you observe a situation where one block is stopped while another is moving, and you notice that the string connecting them becomes taut, it’s a fascinating demonstration of Newton's laws of motion and the principles of tension in a string. Let’s break this down step by step to clarify why this happens.

Understanding the Scenario

Imagine you have two blocks connected by a string. One block is on a surface, while the other is hanging off the edge. When the block on the surface is stopped, the block hanging will still have a tendency to move due to gravity. This is where the tension in the string comes into play.

The Role of Tension

Tension is the force that is transmitted through the string when it is pulled tight by forces acting at either end. When the block on the surface is stopped, the force of gravity acting on the hanging block creates tension in the string. This tension is what causes the string to become taut.

Newton’s Laws in Action

• First Law (Inertia): An object at rest will stay at rest, and an object in motion will stay in motion unless acted upon by a net external force. When the block on the surface is stopped, it remains at rest.
• Second Law (F=ma): The force acting on an object is equal to the mass of that object multiplied by its acceleration. The hanging block experiences a downward force due to gravity, which creates tension in the string.
• Third Law (Action-Reaction): For every action, there is an equal and opposite reaction. The tension in the string pulls on both blocks equally, which is why the string gets tight.

Visualizing the Forces

Think of it like this: when you pull on one end of a rope, the other end feels that pull. In your scenario, when the block on the surface is stopped, the force of gravity on the hanging block tries to pull it down. The string transmits this force, creating tension. If the string were to break or if the block were to suddenly fall, the tension would be released, and the hanging block would accelerate downward.

Real-World Example

Consider a game of tug-of-war. If one team suddenly stops pulling, the rope becomes taut because the other team is still exerting force. The same principle applies here: the motion of one block affects the other through the tension in the string.

Conclusion

In summary, when one block is stopped, the other block connected by the string continues to exert force due to gravity, creating tension in the string. This tension is what causes the string to wind up or become taut. Understanding these principles helps clarify how forces interact in a system, making it a fundamental concept in physics.