Answer
The average force on the wall from the ball is $~~-(180~N)~\hat{j}$
Work Step by Step
In part (a), we found that the impulse on the ball from the wall is $~~(1.8~kg~m/s)~\hat{j}$
We can find the average force on the ball from the wall:
$F~t = J$
$F = \frac{J}{t}$
$F = \frac{(1.8~kg~m/s)~\hat{j}}{10\times 10^{-3}~s}$
$F = (180~N)~\hat{j}$
The average force on the ball from the wall is $~~(180~N)~\hat{j}$
By Newton's Third Law, the average force on the wall from the ball is $~~-(180~N)~\hat{j}$.
