1. The problem statement, all variables and given/known data A boy reaches out of a window and tosses a ball straight up with a speed of 10 m/s. The ball is 20 m above the ground as he releases it. Use energy to find: 1)The ball's maximum height above the ground. 2)The ball's speed as it passes the window on its way down. 3)The speed of impact on the ground. 2. Relevant equations Etotal= PEi+KEi=PEf+KEf Vf2-Vi2=2AD KE=mv2 PE=mgy hmax= v2/ 2g 3. The attempt at a solution I solved for the first part and got it right by using the formula for hmax and got 5.1 ,and then added 20 m and got 25.1 meters which is correct. For the second part I used vf2-vi2=2ad and I got 10 m which is also correct. I am having trouble finding the third one; I tried applying vf2 -vi2=2ad using 20 m and 25.1 m and both of them didn't work. any suggestions.