Answer:
90 N
Explanation:
The force applied to the ball is given by:
\(F=\frac{\Delta p}{\Delta t}\)
where
\(\Delta p\) is the change in momentum of the ball
\(\Delta t\) is the time taken
The change on momentum of the ball is:
\(\Delta p=m\Delta v=(0.45 kg)(20 m/s)=9 kg m/s\)
So, the force applied is
\(F=\frac{9 kg m/s}{0.10 s}=90 N\)