Answer
The linear speed when smooth rolling begins is $~~6.0~m/s$
Work Step by Step
In part (b), we found that the linear acceleration is $-2.1~m/s^2$
In part (d), we found that the ball slides for a time of $1.2~s$
We can find the linear speed when smooth rolling begins:
$v = v_0+at$
$v = (8.5~m/s)+(-2.1~m/s^2)(1.2~s)$
$v = 6.0~m/s$
The linear speed when smooth rolling begins is $~~6.0~m/s$.
