#### Answer

The sled takes 1.2 seconds to travel from point A to point B.

#### Work Step by Step

We can use the impulse-momentum theorem to find the time $t$ to travel from point A to point B. Note that the impulse $J$ is equal to $-F_f~t$, where $F_f$ is the magnitude of the force of friction exerted on the sled.
$p_0+J = p_f$
$p_0-F_f~t = p_f$
$-F_f~t = p_f - p_0$
$-mg~\mu_k~t = m~(v_f-v_0)$
$t = \frac{(v_f-v_0)}{-g~\mu_k}$
$t = \frac{(5.0~m/s-8.0~m/s)}{-(9.80~m/s^2)(0.25)}$
$t = 1.2~s$
The sled takes 1.2 seconds to travel from point A to point B.