A student practices her tennis volleys by hitting a tennis ball against a wall.

 

 ($($a)$)$ If the 0.060$0\mathrm{.}060$ kg ball travels 48$48$ m/$/$s before hitting the wall and then bounces directly backward at 35 m$/$s,$,$ what is the impulse of the interaction?

  

 ($($b)$)$ If the duration of the interaction is 25$25$ s,$,$ what is the average force exerted on the ball by the wall?