(a) The diagram should show three forces: the gravitational force acting downwards, the normal force perpendicular to the plane, and the frictional force opposing the motion.

(b) Resolve forces perpendicular to the plane: \(R = 8g \cos 30^{\circ} = 40\sqrt{3} \approx 69.282\). Resolve forces parallel to the plane and apply Newton's second law: \(8g \sin 30^{\circ} - F = 8 \times 2.4\). This gives \(F = 20.8\). Use \(F = \mu R\) to find \(\mu\):

\(8g \sin 30^{\circ} - 8g \mu \cos 30^{\circ} = 8 \times 2.4\)

\(40 - 40\sqrt{3} \mu = 19.2\)

\(\mu = \frac{20.8}{40\sqrt{3}} \approx 0.3\)

(c) Use the equation \(v^2 = u^2 + 2as\) with \(u = 0\), \(a = 2.4\), and \(s = 3\):

\(v^2 = 2 \times 2.4 \times 3\)

\(v = \sqrt{14.4} \approx 3.79 \text{ m/s}\)