2 A particle \(P\) of mass 0.4 kg is in limiting equilibrium on a plane inclined at \(30 ^ { \circ }\) to the horizontal.
- Show that the coefficient of friction between the particle and the plane is \(\frac { 1 } { 3 } \sqrt { 3 }\).
A force of magnitude 7.2 N is now applied to \(P\) directly up a line of greatest slope of the plane. - Given that \(P\) starts from rest, find the time that it takes for \(P\) to move 1 m up the plane.