Answer
(a) v = 4.48 m/s
(b) v = 3.61 m/s
Work Step by Step
(a) $W = K_2-K_1$
$F~d = \frac{1}{2}mv^2 - 0$
$v^2 = \frac{2F~d}{m}$
$v = \sqrt{\frac{2F~d}{m}}$
$v = \sqrt{\frac{(2)(36.0~N)(1.20~m)}{4.30~kg}}$
$v = 4.48~m/s$
(b) $W = K_2-K_1$
$F~d - mg~\mu_k~d= \frac{1}{2}mv^2 - 0$
$v^2 = \frac{2F~d - 2mg~\mu_k~d}{m}$
$v = \sqrt{\frac{2F~d-2mg~\mu_k~d}{m}}$
$v = \sqrt{\frac{(2)(36.0~N)(1.20~m)-(2)(4.30~kg)(9.80~m/s^2)(0.30)(1.20~m)}{4.30~kg}}$
$v = 3.61~m/s$
