Question

A weight if 20N hangs from a fixed point by a light inextensible string. It is pulled aside by a horizontal force with the string inclined at an angle of 30° to the vertical. What is the tension in the string?

Answer 1

The weight will be in balance when:

$\begin {cases} T \sin \alpha = F \\ T \cos \alpha = mg \end{cases}$ Then $T = \frac{mg}{cos \alpha} = \frac{20N}{\cos (30^\circ)}$ , so

T = 23.09N