Answer
The block travels a distance of $~~9.3~m~~$ across the section with friction.
Work Step by Step
In part (b), we found that the speed at point C is $~~v = 11.3~m/s$
We can find the distance $x$ the block travels across the section with friction:
$mg~\mu~x = \frac{1}{2}mv^2$
$g~\mu~x = \frac{1}{2}v^2$
$x = \frac{v^2}{2~g~\mu}$
$x = \frac{(11.3~m/s)^2}{(2)~(9.8~m/s^2)~(0.70)}$
$x = 9.3~m$
The block travels a distance of $~~9.3~m~~$ across the section with friction.
