Question

A 20 kg weight is suspended from a string. What is the tension on the string

Answer 1

The weight is in equilibrium, so the two forces acting on it (tension T pulling upward, and its own weight W pulling it downward) cancel each other. By Newton's second law,

∑ F = T - W = 0

so that

T = W

Calculate the object's weight:

W = (20 kg) (9.8 m/s²) = 196 N

So the tension is T = 196 N as well.

Answer 2

assume that tension in string a is Ta and in string b is Tb

now taking the component of tensions

Tasin30∘=Tbsin30∘...(1)

it means Ta=Tb

Tacos30∘+Tbcos30∘=mg...(2)

⇒2Tacos30∘=20×10⇒Ta=Tb=3200