Two particles A and B, move with constant velocities `vec(v_(1))" and "vec(v_(2))`. At the initial moment their position vectors are `vec(r_(1))" and "vec(r_(2))` respectively. The condition for particle A and B for their collision is

Options

A. `vec(r_(1))-vec(r_(2))=vec(v_(1))-vec(v_(2))`
B. `(vec(r_(1))-vec(r_(2)))/(|vec(r_(1))-vec(r_(2))|)=(vec(v_(2))-vec(v_(1)))/(|vec(v_(2))-vec(v_(1))|)`
C. `vec(r_(1)).vec(v_(1))=vec(r_(2)).vec(v_(2))`
D. `vec(r_(1))xx vec(v_(1))=vec(r_(2))xx vec(v_(2))`

Answer

B