Two particles `A` and `B` are situated at point `(60,0)` at `t=0`. The particle `A` move on a circle given by `X^(2)+Y^(2)=3600` and with a speed `6 pi m//s`, while `B` moves with a constant velocity.
(`a`) Find the velocity of `B` so that the collision takes places between `A` and `B` at point `(60,0)`.
(`b`) Calculate average acceleration of particle `A` during the motion.