An artillery shell of mass 10.00 kg, lying at rest on the ground, accidentally detonates, exploding into three pieces of shrapnel. One piece of mass 1.60 kg is flung in the -x direction at 22.1 m/s, while a second piece of mass 2.80 kg is propelled in the -y direction at 14.1 m/s. Determine the angle at which the remaining piece of shrapnel travels, relative to the +x axis.