6 A particle \(P\) of mass 2.5 kg strikes a rough horizontal plane. Immediately before \(P\) strikes the plane it has a speed of \(6.5 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) and its direction of motion makes an angle of \(30 ^ { \circ }\) with the normal to the plane at the point of impact. The impact may be assumed to occur instantaneously. The coefficient of restitution between \(P\) and the plane is \(\frac { 2 } { 3 }\). The friction causes a horizontal impulse of magnitude 2 Ns to be applied to \(P\) in the plane in which it is moving.

1. Calculate the velocity of \(P\) immediately after the impact with the plane.
2. \(\quad P\) loses about \(x \%\) of its kinetic energy as a result of the impact. Find the value of \(x\).