Halliday, Resnick & Walker — Motion in Two and Three Dimensions: Problem 20

In Fig. 4.12, particle A moves along the line \( y = 30 \text{ m} \) with a constant velocity \( \vec{v} \) of magnitude \( 3.0 \text{ m/s} \) and parallel to the \( x \) axis. At the instant particle A passes the \( y \) axis, particle B leaves the origin with a zero initial speed and a constant acceleration \( \vec{a} \) of magnitude \( 0.40 \text{ m/s}^2 \). What angle \( \theta \) between \( \vec{a} \) and the positive direction of the \( y \) axis would result in a collision?