The formula for the speed is,
[tex]s=\frac{d}{t}[/tex]Substitute 24 for d and 12 for t in the formula to obtain the speed of ball.
[tex]\begin{gathered} s=\frac{24\text{ ft}}{12\text{ sec}} \\ =2\text{ ft/sec} \end{gathered}[/tex]So speed of the ball is 2 ft/sec.
