A cricketer hits a ball straight up in the air, it leaves the bat at 16.8 ms-1 and has a mass of 160g .
i did part a) and b) they asked for kinetic energy & height
now part c i don't know , the question says
c) if in reality, flying up in the air and back down again is process with an efficiency 88%, the how fast will the ball be traveling when it returns to the start point ?
please could some one explain the process and how exactlly should we solve this ?