(a) Resolve forces parallel to the plane using Newton's second law:

\(T \cos 26^{\circ} - 8g \sin 18^{\circ} - F = 8 \times 0.2\)

Resolve forces perpendicular to the plane:

\(R + T \sin 26^{\circ} = 8g \cos 18^{\circ}\)

Use the friction equation \(F = 0.65R\) to find an equation in \(T\) only.

Solve for \(T\):

\(T = 64 \text{ N}\)

(b) Use the constant acceleration formula to find the distance \(s\) during the fourth second:

\(s = \frac{1}{2} \times 0.2 \times 4^2 - \frac{1}{2} \times 0.2 \times 3^2\)

or

\(s = \frac{1}{2} (0 + 0.2 \times 4) \times 4 - \frac{1}{2} (0 + 0.2 \times 3) \times 3\)

\(Distance = 0.7 m\)