Where needed, use \(g=10\text{ m s}^{-2}\).

A particle \(P\) of mass 0.4 kg lies on a rough horizontal floor with coefficient of friction \(\mu\). A force of 3 N acts upwards at angle \(\alpha\) above the horizontal, where \(\tan\alpha=3/4\). The particle starts from rest and accelerates at \(2\text{ m s}^{-2}\).

(a) Find the time taken to travel 1.44 m from its starting point. [2]

(b) Find \(\mu\). [4]