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 1.70 kg is flung in the -x direction at 21.0 m/s, while a second piece of mass 3.40 kg is propelled in the -y direction at 13.9 m/s. Determine the angle at which the remaining piece of shrapnel travels, relative to the +x axis. b. Calculate the speed of the third piece of shrapnel. I found the momentum for 1 and 2 and I tried to invert those to try to find the third. I'm sort of lost on how to find the angle and such. Thanks in advance.