Question

http://education.cambridge.org/media/649619/mechanics_2_for_ocr.pdf

Answer 1

Example 1.2.3

Answer 2

Can somene explain why we took 2 as the velocity

Answer 3

He didn't . the 2 is the distance off the ground that the ball starts out at because he took the ground ans the reference plane.

Hi general equation distance to hit ground on the opposite side of the net =
\[=\frac{ 1 }{ 2 } g t ^{2} +v _{0} t+ d _{0}\]

where do is set to 2 Vo is zero