I wanna know why when an object is fastened onto a point on a string,the tension in the different parts of the string are different?
When an object is fastened onto a point on a string, the tension in the different parts of the string becomes different due to several factors. To understand why this happens, we need to consider the physics behind it.
When an object is hung from a string, it experiences a downward force due to gravity. This force is applied at the center of mass of the object. However, the object is also attached to the string, which exerts an upward force to support the weight of the object.
When the object is at rest, in equilibrium, the tension in the string varies throughout its length. This is because the string transmits the gravitational force from the object to the point of attachment. The tension in the string is highest at the attachment point and decreases gradually as you move away from it.
To understand how the tension varies, we can analyze a simple example. Consider a mass (m) connected to a string of negligible mass and fixed at a point above the mass. Just below the attachment point, the string carries the entire weight of the mass, resulting in maximum tension. As you move further down, the string only needs to support part of the mass's weight, so the tension decreases.
The reason behind this variation in tension lies in the fact that the string transmits the force equally in all directions at any point along its length. However, as the string moves away from the attachment point, the downward force due to gravity decreases, resulting in decreased tension in the string.
It's important to note that this variation in tension only occurs in situations where the mass is not moving or accelerating. If the object is undergoing motion or there is a net force acting on it, the tension in the string might further change due to these factors.
In summary, when an object is fastened onto a point on a string, the tension in the different parts of the string varies because the string transmits the gravitational force from the object equally in all directions, resulting in a decrease in tension as you move away from the point of attachment.