$2.)(6$ Points$)$ Determine the time needed for the load at $"B"$ to attain a speed of $15\frac{m}{s},$ starting from

rest, if the cable is drawn into the motor with an acceleration of $a_A=0\mathrm{.}6t\frac{m}{s^2}$ where $"$ t $"$ is the

time in seconds.