Consider the given scenario in which block, block is suspended, scenario in which a block is suspended with the help of a string. The mass of the block is 10 kg. Listen carefully, this 10 kg block will experience a downward force due to the gravity, I think we all know that. So there will be a force in downward direction, which is known as the weight and that weight is equal to mass of the object multiplied by the famous acceleration due to gravity. So, this 10 kg block will experience, so here we are taking g as 10 not 9.8, okay. So this block is having weight 100 Newton, weight is the force so its unit must be Newton, so 100 Newton force will be applied on the block. It means the ground is pulling this object downward with 100 Newton force.  But the block is at rest, can we see that, the block is at rest. And if the block is at rest that means what is the total force on the block. Must be zero, total force zero means what, that if somebody is pulling downward that means something is pulling upward.  And which object can pull this block upward, the only option is string. So first of all, we will see the force of string, the force of the string, we call it as Tension and we represent it as T. And what is the technique to find the direction of Tension in a string. Where will the string put the Tension, there is one technique to find out. Its name is ‘Cut and Pull’. Think how, virtually we will cut this string and then you pull the end. And now tell where will you pull it? Don’t use physics in this, use logic used in daily life. Where will you pull the end, where will the Tension force come? Downward. Wherever you will pull the string there the Tension will come, done, where will you pull this end. There is only one option.  Does anybody have any other options? Can anybody pull it down, it has to be upward. So T and T, T or 100, they must be equal because the block is in equilibrium or the block is at rest.  Equilibrium means net force is zero, rest means net force zero. So the T must be equal to 100 Newton. With the help of this particular example, I want to just give you this idea, how to find the Tension in the string, done, technique Cut and Pull.

Let us consider one more scenario. Let us consider one more case in which a block is at rest. The block is at the rest with the help of three different strings. Then find Tension in each string, okay.