A box slides from rest down a slope 5.5 m long, at 32° to the horizontal…

Step 1. Acceleration. $a = 9.8\ \text{m/s}^2 \times (0.530 - 0.18 \times 0.848) = 9.8\ \text{m/s}^2 \times 0.377 = 3.70\ \text{m/s}^2$.

Step 2. Speed. $v = \sqrt{2 \times 3.70\ \text{m/s}^2 \times 5.5\ \text{m}} = 6.38\ \text{m/s}$.