In a minor rail yard accident, a runaway goods truck of mass 1.85 104 kg collides at u = 20.0ms-1 with a stationary truck of mass 2.20 104 kg. The trucks lock together and travel at the same speed after the collision. The truck's linear velocity vector is in the positive x-direction using the Cartesian coordinate system shown in Figure 3. What is the direction of the wheel's angular momentum vector? Briefly explain your reasoning