Question

On a spacecraft two engines fire for a time of 748 s. One gives the craft an acceleration in the x direction of ax = 5.21 m/s2, while the other produces an acceleration in the y direction of ay = 3.45 m/s2. At the end of the firing period, the craft has velocity components of vx = 5390 m/s and vy = 3470 m/s. Find (a) the magnitude and (b) the direction of the initial velocity. Express the direction as an angle with respect to the +x axis.