(a) Using the equation of motion \(s = ut + \frac{1}{2} a t^2\), where \(u = 0\), \(s = 1.44\) m, and \(a = 2\) m/s\(^2\):

\(1.44 = 0 + \frac{1}{2} \times 2 \times t^2\)

\(1.44 = t^2\)

\(t = \sqrt{1.44} = 1.2 \text{ s}\)

(b) Resolve forces vertically to find the normal reaction \(R\):

\(R = 0.4g - 3 \times \frac{3}{5} = 0.4g - 3 \sin 36.9^\circ \approx 2.2 \text{ N}\)

Resolve forces horizontally using Newton's second law:

\(3 \times \frac{4}{5} - F = 3 \cos 36.9^\circ - F = 0.4 \times 2\)

\(F = 1.6 \text{ N}\)

Using \(\mu = \frac{F}{R}\):

\(\mu = \frac{1.6}{2.2} \approx 0.727\)