5.
\includegraphics[max width=\textwidth, alt={}, center]{42695f57-bf7a-4cf7-b05f-f76b0a85d82d-3_517_745_1387_792} A box of mass 1.5 kg is placed on a plane which is inclined at an angle of \(30 ^ { \circ }\) to the horizontal. The coefficient of friction between the box and plane is \(\frac { 1 } { 3 }\). The box is kept in equilibrium by a light string which lies in a vertical plane containing a line of greatest slope of the plane. The string makes an angle of \(20 ^ { \circ }\) with the plane, as shown in Fig. 2. The box is in limiting equilibrium and is about to move up the plane. The tension in the string is \(T\) newtons. The box is modelled as a particle. Find the value of \(T\).