Ball A is thrown from a point O on level ground at $30\ \text{m/s}$, at $53^\circ$ above the horizontal, towards a point Q on the ground $60\ \text{m}$ away. At the same instant, ball B is thrown from Q, in the same vertical plane, so that the two balls hit each other in the air, as shown in the figure. Ignore air resistance, and take $g = 10\ \text{m/s}^2$, $\sin 53^\circ = 0.8$ and $\cos 53^\circ = 0.6$. With what least speed, and in what direction, can B be thrown, and how high above the ground do the balls then meet?

Fig. 1: Level ground with point O on the left and point Q 60 m to the right. Ball A is thrown from O at 30 m/s at 53 degrees above the horizontal, towards Q. Ball B is at Q, and is thrown at the same instant, in a direction marked with a question mark.