This was a question on a mechanics exam. Part i wants me to assume that the tension in both parts of the string is the same. Even though I got the correct answer( 18.9N) by assuming so, I don't understand how this assumption makes sense. Consider the bit of string under the ring. The net force on it must be zero ( light string ) so that implies the net vertical component is zero. This is not possible if I assume the tensions to be the same, or at least that's how I see it ( see image)
Basically in my mind: If the tensions are equal, the net force on the bit in contact with the ring can not be zero since the angles are different. But since the string is light, this does not add up. ( Or the system is at rest. Net force on that bit of rope must be zero, regardless of light/ not light)
But the question assumes the opposite. I would like to know what part of my argument here is flawed.