Answer
The final speed is 3.99 m/s.
Work Step by Step
$W = K_2 - K_1$
$mg~d~cos(53.1^{\circ}) = \frac{1}{2}mv^2 - 0$
$v^2 = 2g~d~cos(53.1^{\circ})$
$v = \sqrt{2g~d~cos(53.1^{\circ})}$
$v = \sqrt{(2)(9.80~m/s^2)(1.35~m)~cos(53.1^{\circ})}$
$v = 3.99~m/s$
The final speed is 3.99 m/s.
