A tennis player serves to the match point. He hits the ball so that it

leaves the racket horizontally. The ball then passes the $90$ cm high net $15$ cm above the edge of the net. For the following calculations, air friction should be ignore. the acceleration due to gravity g acts at $9\mathrm{.}81$ m$/$s$.$

a$)$Calculate the speed v at which the ball must have left the racket?

b$)$At what distance will the ball land behind the net?

S- 0,9 V. 11,7 2,55 +