3
\includegraphics[max width=\textwidth, alt={}, center]{57725055-7bce-4ad0-bb1c-59d07d56e2bd-2_350_1025_1704_559} The diagram shows a small block \(B\), of mass 3 kg , and a particle \(P\), of mass 0.8 kg , which are attached to the ends of a light inextensible string. The string is taut and passes over a small smooth pulley. \(B\) is held at rest on a horizontal surface, and \(P\) lies on a smooth plane inclined at \(30 ^ { \circ }\) to the horizontal. When \(B\) is released from rest it accelerates at \(0.2 \mathrm {~m} \mathrm {~s} ^ { - 2 }\) towards the pulley.

1. By considering the motion of \(P\), show that the tension in the string is 3.76 N .
2. Calculate the coefficient of friction between \(B\) and the horizontal surface.