Answer:
[tex]J=P_2-_{}P_1=0[/tex]Explanation: To redirect the ball, or reverse its direction, the Impulse required would be:
[tex]\Delta P=0\rightarrow\text{ For the Ball}[/tex]Because the initial and final velocity should remain the same:
[tex]\begin{gathered} \text{ The Impulse required would be:} \\ \Delta P=P_2-_{}P_1 \\ P_2=_{}P_1\Rightarrow P=(1.9\operatorname{kg})\cdot(21ms^{-1})=39.9\cdot(kg\cdot m\cdot s^{-1}) \\ \therefore\Rightarrow \\ \Delta P=0 \end{gathered}[/tex]