Constant-Velocity Vector Motion (HL only)

For a particle moving with constant velocity v, position at time t is r(t)= r_0+t v, with speed | v|. Use compatible units for time and coordinates. Two paths may intersect without a collision. For a collision, both position vectors must agree at the same time. For a path intersection, use independent parameters. Example r_A(t)= 0 0 +t 2 1, r_B(t)= 6 0 +t -1 1. 2t=6-t gives t=2, and both second coordinates are 2. The particles collide at (4,2). Their speeds are 5 and 2 distance units per time unit.